6 Pack of Universal Security Instruments Plug-In 2-in-1 Carbon Monoxide and Natural Gas Smart Alarms with Battery Backup
- 2-in-1 Carbon Monoxide and Natural Gas Alarm
- 120-Volt AC Plug-In Alarm with Battery Back-Up
- Back-up Battery Continues protection in the event of a power outage
- 9-Volt Energizer Alkaline Battery Included
- Power and Alarm LED's
- Compact Plug-in Design
- No Additional Mounting Required
- Swift Installation Process
- Microprocessor Software Eliminates Nuisance Alarms
- 5 Year Limited Warranty
- Meets New Laws & Legislations - This alarm exceeds industry standards, and is listed to UL Standard UL 217 and is California State Fire Marshal approved.
Carbon Monoxide and Natural Gas Protection
The Universal Security Instruments Electric MCND400B Smart Alarm provides essential dual protection for your home and family, guarding against both carbon monoxide (CO) and natural gas. This 2-in-1 device simplifies installation, combining two critical detection functions into one compact unit. Its convenient plug-in design means it easily fits into any standard electrical outlet, requiring no professional installation. This makes the alarm a perfect safety solution for various residences, including homes, apartments, and mobile homes.
Intelligent Detection and Essential Features
This smart alarm is equipped with microprocessor intelligence to analyze carbon monoxide readings, ensuring reliable detection while significantly reducing the likelihood of false alarms. Beyond CO, the unit also functions as a dedicated natural gas detector, providing an early warning of potential gas leaks. For long term peace of mind, this plug-in detector includes an end-of-service life warning, alerting you when it's time for a replacement (approximately 7 years after activation). A 9-volt alkaline battery (included) provides crucial backup power, maintaining protection even during power outages.
Certified Safety and Installation Guidelines
The USI Carbon Monoxide and Natural Gas Alarm is built to exceed industry standards, being ETL Listed to UL Standard 2034 & UL1484, approved by the California State Fire Marshal, and Federal Housing Authority (FHA) approved. To ensure maximum protection, it is recommended to install an alarm inside every bedroom, outside all sleeping areas, and on all levels of your home. The Universal Security Instruments Electric MCND400B Smart Alarm comes with a 5-year limited warranty, offering added assurance for your home's safety.
Recommended replacement for the following obsolete models:
- CD-9590
- If the Alarm is exposed to 400 ppm of CO, it must alarm between 4 and 15 minutes.
- If the Alarm is exposed to 150 ppm of CO, it must alarm between 10 and 50 minutes.
- If the Alarm is exposed to 70 ppm of CO, it must alarm between 60 and 240 minutes.
- Warranty: 5 year Limited Warranty
- Alarms Power Source: 120 volt (plug In & battery backup)
- Alarm Sensor Type: Metal Oxide
- Manufacturing Credits: ISO 9001 certified factory, UL listed & CSFM listed
- Packaging: Easy Open Box Packaging
- Product Dimensions (W x H x D): 2.25 x 4.25 x 1.25 in.
- Product Weight: 0.52 lbs.
If you are interested in ordering a large quantity of items you may qualify for volume pricing discounts. Volume Discount Pricing is a great way for customers to save big on large, bulk orders of most items available in our store. Please send a bulk order request to our friendly sales staff so they may create a quote and provide personal service for your order! You will receive a response within 1-2 business days and our office hours are Monday through Friday, 8am-5pm CST.
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- Get a detailed quote from a dedicated sales rep.
- Our warehouse ships directly to you.
- You enjoy the savings & are now a preferred customer.

USI Plug-In 2-in-1 CO and Natural Gas Smart Alarm with Battery Backup Reviews
Works great, easy to install, lasts for years.
I had a Universal Security Carbon Monoxide and Natural Gas Alarm for 7 years when it reached the end of its lifespan. I purchased a new replacement and had difficulty getting it to work properly. I reached out to the customer service department who promptly sent a replacement. The new one works great! The company stands behind their products and treat the customer with respect.
This plug in carbon monoxide, natural gas detector assures me peace of mind.
The product arrived exactly as ordered and on time. It was very easy to plug it in to the wall and testing it was also very easy. It was reasonably priced and adds allot of safety to my home.
I purchased two 2 in 1 Carbon Monoxide and Natural Gas Smart Alarms. One of the CO/Gas detectors became defective after about three weeks, the CO sensor kept going off. There was clearly no CO in the area, and since I had two of the detectors, I swapped locations and the bad sensor still went off. I need a replacement for that one. Otherwise I was happy with the purchase and the ease of install.
Response:Hello, Nahan. We're sorry to hear this. Please reach out to us here and we'll get this resolved for you.
The dual alarm is the best out there!
I purchased the USI Plug-In, 2-in-1 CO and Natural Gas Smart Alarm with Battery Backup MCN400B for my son's new residence. I have a couple of them in my home. We both have natural gas appliances throughout heating, hot water, etc. and that always means the possibility of carbon monoxide if anything goes wrong. Or the possibility of a natural gas leak. Carbon monoxide CO is an odorless, colorless gas formed by incomplete combustion and displaces oxygen leading to poisoning and death. But with this Universal Security Instruments CO and Natural Gas Smart Alarm, I know that my family is protected from both of these dangers by this highly reputable and trustworthy company. That's why we have these and other Universal Security Instruments products. This CO and Natural Gas Smart Alarm is indeed an absolutely marvelous safety device and now that my son has his own residence, I want him to be afforded the same protection that the rest of my family has always had. This USI Plug-In, 2-in-1 CO and Natural Gas Smart Alarm with Battery Backup is the very best anywhere. I think of it like this : have you ever had water leak in your home? Most people have at one time of another. Well, you could just as easily have a natural gas leak or a carbon monoxide leak in your home. At least with a water leak, the worst thing that can happen is your house gets flooded. But with a natural gas leak or a carbon monoxide leak, you might die in your sleep. That's why when my family is sleeping, I want the USI Plug-In, 2-in-1 CO and Natural Gas Smart Alarm with Battery Backup to be watching out for us. While my family sleeps, this alarm is always on guard.
Works well and easy to use.
Works as advertised and shipped quickly
Very good