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Universal Security Instruments

Model # MCND401B

Internet # 203367046

Plug-In Combination Carbon Monoxide and Natural Gas Alarm

This item has been discontinued.
The Home Depot no longer carries this specific product.

Was   $31.82
$29.00 /each
(limit 10 per order)

Save $2.82 (9%) through 12/06/2015

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Promotion Details
Price Valid : 11/26/2015 - 12/06/2015
Holiday Savings
  • Dual sensor detects carbon monoxide and natural gas
  • Compact, easy-to-use, plug-in design
  • Display screen shows carbon monoxide level




Model # MCND401B

Internet # 203367046

Offering single installation and double protection, this compact plug-in alarm is perfect for new or replacement installations. The dual sensing alarm provides protection against two deadly household threats, carbon monoxide and natural gas, with a display screen that shows the level of carbon monoxide detected. This alarm is suitable for installation in houses, apartments and mobile homes. Early warning of carbon monoxide and natural gas is best achieved by installing combination alarms on every level of your dwelling, including basements. For maximum protection, install an alarm inside every bedroom and outside every sleeping area as well.

  • Three LED colors indicate status of power, carbon monoxide and natural gas
  • Compact design covers only one outlet
  • Ideal for every room in your home
  • Plugs into standard outlet; no additional mounting required
  • Fast and easy to install
  • Backup battery provides protection even during a power outage
  • 9-volt EVEREADY alkaline battery included
  • Large, bright digital screen displays carbon monoxide level

Info & Guides

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Coverage area (sq. ft) 
Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 
Alarm Type 
Carbon Monoxide,Natural Gas 
Alarm/Detector Features 
Battery Back-Up,Digital display 
Calibration (% of LEL) 
Connector/Contact Type 
Fixed or portable 
Gas(es) detected 
Carbon monoxide 
Minimum detection (ppm) 
Power Source 
Response time (sec.) 
Voltage (volts) 
Warranty / Certifications
Certifications and Listings 
1-UL Listed 


Rated 3.2 out of 5 by 11 reviewers.
Rated 1.0 out of 5.0 by Don't count on this to detect Natural Gas! google the model# MCND401B and look at the reviews on Amazon...the first on has a video of guy waving this "Natural gas" alarm over an unlit stove with the gas alarm. I bought this from HD despite having big doubts over whether it works...Perhaps the guy got a bad happens. When I got the alarm, I pulled the tag blocking the battery, pushed the test buttons to confirm it was live and replicated the test in the video...waving the alarm directly over an unlit burner with gas gushing out. Narry a peep from the alarm...just like in the video. Back to HD it went. September 2, 2013
Rated 2.0 out of 5.0 by Not as advertised Battery stated on package was an Ion battery but all I got was a regular 9 v August 25, 2015
Rated 1.0 out of 5.0 by Not a reliable product. Gave a false natural gas alert. Not a reliable system. I recommend looking for a alternate alarm option. March 1, 2015
Rated 1.0 out of 5.0 by horrible product I purchase 20 of these units and 6 have went bad within the past year. I've contacted USI electronics customer service on multiple occasions and their only solution is send it back. That's after I contacted them 3 or 4 times. Stay clear of this product. It will go off at odd times for no reason. VENTTEX Inc. -an off duty fireman company- December 4, 2014
Rated 5.0 out of 5.0 by A must have for your home! I had given this alarm to my daughter and her family several years ago. Two weeks ago the alarm started going off and the word GAS was shown on the digital display. The firemen checked out their home and found a gas leak in their oven and a problem with their furnace. Yes, both at the same time. I bought this alarm to replace the older one per the advice of the firemen. This is the only brand I would buy. I have two of them in my home and have given them to my sisters as well. November 11, 2014
Rated 5.0 out of 5.0 by Just right I bought this a part of the installation of my tankless water heater. It's great that it covers only one electrical outlet (allowing me the plug the tankless water heater into the other one) yet gives me the comfort of knowing I'm covered for both natural gas and carbon monoxide alarms. I didn't find any lower prices than through Home Depot, and shipping was quick, complete with a return shipping sticker if needed. That's great, proactive customer service. April 9, 2013
Rated 4.0 out of 5.0 by It works, I'm not an expert, but it's easy It plugs into an outlet and does the job of monitoring gas levels and CO. I have it in the downstairs hallway and it is very loud, so it should wake up most of the house if there is danger. We had an incident before I bought the detector and a cook-stove was not turned off all the way, so it leaked gas the whole day downstairs and I couldn't smell it upstairs, however when my husband came home, he could smell the gas from outside and told me to put my coat on and my baby's coat on and to get outside. We're very fortunate that the old house was drafty and didn't blow up. March 12, 2013
Rated 1.0 out of 5.0 by just plane junk!! this unit is just plane junk i would not trust it to protect my life December 23, 2014
  • 2015-11-26 T12:05:35.176-06:00
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