Master Lock 140D Solid Brass Keyed Different Padlock with 1-9/16-Inch Wide Body, 1/4-Inch Shackle

I bought this model 2 years ago and it has worked without issue. Good to have two sensor types to pickup varied gases/smoke from smouldering vs flaming fires. Wish they made this in a CO detect combo option. No change in my utility bills noticed LOL (i am an energy engineer)

I have had these for 5 years in bedrooms with no issues. Previous post stated these are junk and do not buy is not accurate. All specs and installation sheets specifically state that these are NOT to be installed in a kitchen area or entrance to a kitchen area as it will cause false alarms. User bears the responsibility to properly install these devices as per the recommendations. This post was due to misapplication of the product not a defective product. Dual sensor alarms are very sensitive to detect 2 types of fires and are designed for bedrooms.

I've been using this model PI2010 for over 10 years. They were recommended by a major magazine doing product reviews. They have been solid and problem free, with no false alarm and no need for maintenance. On the other hand, the P4010ACS have too many false alarm. As more of my PI2010 are getting over 10 year old, I plan to buy more of them... Unfortunately, the price has significantly gone up in the mean time :-(

I installed these 3 years ago so far I have had 3 of the 3 duel sensor just set false alarms any time day or night. I have replaced 2 now I need the 3rd replaced. I think I need to find something more reliable. I also have a heat and co/smoke they have not failed yet.

I kept getting false alarms, even though there was no fire, no smoke, nobody was cooking. I then realized it was going off when someone showers, or when the humidity in the air is high - as might house gets high humidity. The false alarms have forced me to unplug this unit so it is now useless.

UTTER GARBAGE!!!!! WAY TOO SENSITIVE!!! Even toasting a single slice if bread would cause alarms. Had to keep an electric fan close by to ventilate the unit when doing ANY work in my kitchen. Final straw: was baking a pizza at midnight when all alarms went off; tried ventilating the unit closest to kitchen, no effect; tried the test and light-up buttons, no effect; went round the house with my step ladder pulling each unit out of its ceiling mount, no effect; one unit was still active when pulled from its mount, could not pry open the battery door, in desperation put the unit on the floor, jumped a couple of feet in the air and brought my 235 pounds down on the housing which FINALLY knocked out the battery ... SILENCE, but not before my neighbor knocked on my door to see if I was alright. DO NOT BUY ANY KIDDE PRODUCT!!!!!!!!