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FirstAlert

First Alert 9120B / SMI100-AC Smoke Detector, Hardwired Alarm with Battery Backup, 3-Pack

First Alert 9120B / SMI100-AC Smoke Detector, Hardwired Alarm with Battery Backup, 3-Pack

$150.02
$115.40 LIMITED TIME SALE 🔥
Quantity
🛒
Sep 14 Order Placed
⚙️
1–2
Days
Order Processing
📦
Sep 18 -
Sep 22
Estimated Delivery

About This

  • Keep your family safe with this 3 pack of hardwired smoke alarms; the battery backup means constant monitoring, even if there's a power failure
  • Equipped with an ionization sensor, this smoke alarm reliably detects smoke from fast flaming fires and alerts you with an 85 decibel alarm
  • To ensure complete protection make sure to place one on each level of your home and in each bedroom
  • Can connect to other compatible BRK or First Alert smoke detectors, to ensure all alarms will sound when smoke is detected
  • Simple to use, with a single test/silence button, and side load battery compartment; Tamper resistant locking brackets and universal mounting brackets make installation easy
  • Rigorously tested to meet UL standards
  • Faster turnarounds on job sites with the easy to install, most trusted alarms in home safety
  • First Alert has been the most trusted brand in home safety since launching the first residential smoke alarm in 1958 (Based on a First Alert Brand Trust Survey in February 2018)

Overview

  • Brand : First Alert
  • Style : Standard Detection
  • Power Source : Battery Powered,Hardwired
  • Color : White
  • Product Dimensions : 1.9"D x 5.6"W x 5.6"H
  • Item Weight : 9.6 ounces
  • Sensor Type : Ionization
  • Global Trade Identification Number : 00029054018489
  • Unit Count : 3 Count
  • Number of Items : 3
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100% REAL REVIEWS

Reviews Our Brands Got

D

David C.

2026.01.04

I was hesitant because of the price, but this desk completely surprised me. Setup was a breeze—the instructions were clear, and it took me less than 40 minutes by myself. I have a dual-monitor arm holding two screens along with my laptop, and it handles the weight with zero wobbling. The motor lifts smoothly and quietly without shaking everything on top. My back and neck already feel much better during long workdays. Absolutely worth every penny!

S

Sarah Jenkins

2026.05.22

Everything you need for assembly comes right in the box. The size is compact enough to fit nicely in my small home office corner while still offering plenty of room for all my work essentials. The transition between sitting and standing is fast and quiet. If you're looking for an affordable, high-quality motorized desk that doesn't break the bank, this is definitely the one to get.

B

Brian Miller

2026.04.27

Been using it daily for a few weeks now. The frame feels heavy and well-anchored, so there's no noticeable shake even at standing height with a heavy monitor setup. The finish looks clean and modern. It’s hard to find a sturdy electric standing desk at this price point, but this one definitely delivers. Highly recommended for anyone working from home!

M

Marcus Vance

2025.11.08

was a bit skeptical at this price point, but it completely blew me away. I mounted a heavy dual-monitor arm (27" and 32") along with my mechanical keyboard and laptop, and the frame doesn't wobble at all. Assembly took around 35 minutes since the included tools and directions were foolproof. The motor transitions up and down fast and silently. My daily lower back fatigue has significantly improved since switching between sitting and standing throughout the workday.

D

David C.

2026.01.04

I was hesitant because of the price, but this desk completely surprised me. Setup was a breeze—the instructions were clear, and it took me less than 40 minutes by myself. I have a dual-monitor arm holding two screens along with my laptop, and it handles the weight with zero wobbling. The motor lifts smoothly and quietly without shaking everything on top. My back and neck already feel much better during long workdays. Absolutely worth every penny!

S

Sarah Jenkins

2026.05.22

Everything you need for assembly comes right in the box. The size is compact enough to fit nicely in my small home office corner while still offering plenty of room for all my work essentials. The transition between sitting and standing is fast and quiet. If you're looking for an affordable, high-quality motorized desk that doesn't break the bank, this is definitely the one to get.

B

Brian Miller

2026.04.27

Been using it daily for a few weeks now. The frame feels heavy and well-anchored, so there's no noticeable shake even at standing height with a heavy monitor setup. The finish looks clean and modern. It’s hard to find a sturdy electric standing desk at this price point, but this one definitely delivers. Highly recommended for anyone working from home!

M

Marcus Vance

2025.11.08

was a bit skeptical at this price point, but it completely blew me away. I mounted a heavy dual-monitor arm (27" and 32") along with my mechanical keyboard and laptop, and the frame doesn't wobble at all. Assembly took around 35 minutes since the included tools and directions were foolproof. The motor transitions up and down fast and silently. My daily lower back fatigue has significantly improved since switching between sitting and standing throughout the workday.

D

David C.

2026.01.04

I was hesitant because of the price, but this desk completely surprised me. Setup was a breeze—the instructions were clear, and it took me less than 40 minutes by myself. I have a dual-monitor arm holding two screens along with my laptop, and it handles the weight with zero wobbling. The motor lifts smoothly and quietly without shaking everything on top. My back and neck already feel much better during long workdays. Absolutely worth every penny!

S

Sarah Jenkins

2026.05.22

Everything you need for assembly comes right in the box. The size is compact enough to fit nicely in my small home office corner while still offering plenty of room for all my work essentials. The transition between sitting and standing is fast and quiet. If you're looking for an affordable, high-quality motorized desk that doesn't break the bank, this is definitely the one to get.

B

Brian Miller

2026.04.27

Been using it daily for a few weeks now. The frame feels heavy and well-anchored, so there's no noticeable shake even at standing height with a heavy monitor setup. The finish looks clean and modern. It’s hard to find a sturdy electric standing desk at this price point, but this one definitely delivers. Highly recommended for anyone working from home!

M

Marcus Vance

2025.11.08

was a bit skeptical at this price point, but it completely blew me away. I mounted a heavy dual-monitor arm (27" and 32") along with my mechanical keyboard and laptop, and the frame doesn't wobble at all. Assembly took around 35 minutes since the included tools and directions were foolproof. The motor transitions up and down fast and silently. My daily lower back fatigue has significantly improved since switching between sitting and standing throughout the workday.

D

David C.

2026.01.04

I was hesitant because of the price, but this desk completely surprised me. Setup was a breeze—the instructions were clear, and it took me less than 40 minutes by myself. I have a dual-monitor arm holding two screens along with my laptop, and it handles the weight with zero wobbling. The motor lifts smoothly and quietly without shaking everything on top. My back and neck already feel much better during long workdays. Absolutely worth every penny!

S

Sarah Jenkins

2026.05.22

Everything you need for assembly comes right in the box. The size is compact enough to fit nicely in my small home office corner while still offering plenty of room for all my work essentials. The transition between sitting and standing is fast and quiet. If you're looking for an affordable, high-quality motorized desk that doesn't break the bank, this is definitely the one to get.

B

Brian Miller

2026.04.27

Been using it daily for a few weeks now. The frame feels heavy and well-anchored, so there's no noticeable shake even at standing height with a heavy monitor setup. The finish looks clean and modern. It’s hard to find a sturdy electric standing desk at this price point, but this one definitely delivers. Highly recommended for anyone working from home!

M

Marcus Vance

2025.11.08

was a bit skeptical at this price point, but it completely blew me away. I mounted a heavy dual-monitor arm (27" and 32") along with my mechanical keyboard and laptop, and the frame doesn't wobble at all. Assembly took around 35 minutes since the included tools and directions were foolproof. The motor transitions up and down fast and silently. My daily lower back fatigue has significantly improved since switching between sitting and standing throughout the workday.

D

David C.

2026.01.04

I was hesitant because of the price, but this desk completely surprised me. Setup was a breeze—the instructions were clear, and it took me less than 40 minutes by myself. I have a dual-monitor arm holding two screens along with my laptop, and it handles the weight with zero wobbling. The motor lifts smoothly and quietly without shaking everything on top. My back and neck already feel much better during long workdays. Absolutely worth every penny!

S

Sarah Jenkins

2026.05.22

Everything you need for assembly comes right in the box. The size is compact enough to fit nicely in my small home office corner while still offering plenty of room for all my work essentials. The transition between sitting and standing is fast and quiet. If you're looking for an affordable, high-quality motorized desk that doesn't break the bank, this is definitely the one to get.

B

Brian Miller

2026.04.27

Been using it daily for a few weeks now. The frame feels heavy and well-anchored, so there's no noticeable shake even at standing height with a heavy monitor setup. The finish looks clean and modern. It’s hard to find a sturdy electric standing desk at this price point, but this one definitely delivers. Highly recommended for anyone working from home!

M

Marcus Vance

2025.11.08

was a bit skeptical at this price point, but it completely blew me away. I mounted a heavy dual-monitor arm (27" and 32") along with my mechanical keyboard and laptop, and the frame doesn't wobble at all. Assembly took around 35 minutes since the included tools and directions were foolproof. The motor transitions up and down fast and silently. My daily lower back fatigue has significantly improved since switching between sitting and standing throughout the workday.

D

David C.

2026.01.04

I was hesitant because of the price, but this desk completely surprised me. Setup was a breeze—the instructions were clear, and it took me less than 40 minutes by myself. I have a dual-monitor arm holding two screens along with my laptop, and it handles the weight with zero wobbling. The motor lifts smoothly and quietly without shaking everything on top. My back and neck already feel much better during long workdays. Absolutely worth every penny!

S

Sarah Jenkins

2026.05.22

Everything you need for assembly comes right in the box. The size is compact enough to fit nicely in my small home office corner while still offering plenty of room for all my work essentials. The transition between sitting and standing is fast and quiet. If you're looking for an affordable, high-quality motorized desk that doesn't break the bank, this is definitely the one to get.

B

Brian Miller

2026.04.27

Been using it daily for a few weeks now. The frame feels heavy and well-anchored, so there's no noticeable shake even at standing height with a heavy monitor setup. The finish looks clean and modern. It’s hard to find a sturdy electric standing desk at this price point, but this one definitely delivers. Highly recommended for anyone working from home!

M

Marcus Vance

2025.11.08

was a bit skeptical at this price point, but it completely blew me away. I mounted a heavy dual-monitor arm (27" and 32") along with my mechanical keyboard and laptop, and the frame doesn't wobble at all. Assembly took around 35 minutes since the included tools and directions were foolproof. The motor transitions up and down fast and silently. My daily lower back fatigue has significantly improved since switching between sitting and standing throughout the workday.

D

David C.

2026.01.04

I was hesitant because of the price, but this desk completely surprised me. Setup was a breeze—the instructions were clear, and it took me less than 40 minutes by myself. I have a dual-monitor arm holding two screens along with my laptop, and it handles the weight with zero wobbling. The motor lifts smoothly and quietly without shaking everything on top. My back and neck already feel much better during long workdays. Absolutely worth every penny!

S

Sarah Jenkins

2026.05.22

Everything you need for assembly comes right in the box. The size is compact enough to fit nicely in my small home office corner while still offering plenty of room for all my work essentials. The transition between sitting and standing is fast and quiet. If you're looking for an affordable, high-quality motorized desk that doesn't break the bank, this is definitely the one to get.

B

Brian Miller

2026.04.27

Been using it daily for a few weeks now. The frame feels heavy and well-anchored, so there's no noticeable shake even at standing height with a heavy monitor setup. The finish looks clean and modern. It’s hard to find a sturdy electric standing desk at this price point, but this one definitely delivers. Highly recommended for anyone working from home!

M

Marcus Vance

2025.11.08

was a bit skeptical at this price point, but it completely blew me away. I mounted a heavy dual-monitor arm (27" and 32") along with my mechanical keyboard and laptop, and the frame doesn't wobble at all. Assembly took around 35 minutes since the included tools and directions were foolproof. The motor transitions up and down fast and silently. My daily lower back fatigue has significantly improved since switching between sitting and standing throughout the workday.

D

David C.

2026.01.04

I was hesitant because of the price, but this desk completely surprised me. Setup was a breeze—the instructions were clear, and it took me less than 40 minutes by myself. I have a dual-monitor arm holding two screens along with my laptop, and it handles the weight with zero wobbling. The motor lifts smoothly and quietly without shaking everything on top. My back and neck already feel much better during long workdays. Absolutely worth every penny!

S

Sarah Jenkins

2026.05.22

Everything you need for assembly comes right in the box. The size is compact enough to fit nicely in my small home office corner while still offering plenty of room for all my work essentials. The transition between sitting and standing is fast and quiet. If you're looking for an affordable, high-quality motorized desk that doesn't break the bank, this is definitely the one to get.

B

Brian Miller

2026.04.27

Been using it daily for a few weeks now. The frame feels heavy and well-anchored, so there's no noticeable shake even at standing height with a heavy monitor setup. The finish looks clean and modern. It’s hard to find a sturdy electric standing desk at this price point, but this one definitely delivers. Highly recommended for anyone working from home!

M

Marcus Vance

2025.11.08

was a bit skeptical at this price point, but it completely blew me away. I mounted a heavy dual-monitor arm (27" and 32") along with my mechanical keyboard and laptop, and the frame doesn't wobble at all. Assembly took around 35 minutes since the included tools and directions were foolproof. The motor transitions up and down fast and silently. My daily lower back fatigue has significantly improved since switching between sitting and standing throughout the workday.

With Adaptform Studio

Frequently Asked Questions

Absolutely. Every product at Adaptform Studio—from our hydraulic lift-top furniture to our portable aluminum desk stands—undergoes strict weight and stress testing. Whether you are placing dual monitors on our lift tables or mounting heavy tablets and cameras on our mobile arms, our gear is engineered with heavy-duty structural stability for everyday deep work.

We currently ship exclusively within the United States. To ensure the fastest possible fulfillment, all our inventory is stored across premier nationwide fulfillment centers in the US (including Amazon fulfillment hubs). Specific delivery timelines are listed on each product's detail page, and most orders reliably arrive within 10 business days with real-time tracking.

Shipping rates are calculated based on your delivery distance within the United States. For over 99% of standard domestic orders, a flat shipping rate of $4.90 USD applies. However, rates may vary slightly for remote areas, non-contiguous states (such as Alaska and Hawaii), or specific regional zones, which will be accurately calculated and displayed at checkout once your address is entered.

We want you to feel completely confident in your purchase:

  • Defective or Shipping Errors: If an item arrives damaged, defective, or incorrect due to our error, we will cover 100% of the return shipping costs and issue an immediate replacement or full refund.
  • Customer Change of Mind: If you decide to return a product due to personal preference or sizing, returns are accepted in original condition within 30 days. A standard return shipping & restocking fee will be deducted from your final refund amount.