First Alert BRK SMCO210, 10-Year Sealed Battery Combination Smoke & Carbon Monoxide Alarm with Slim Profile Design, 1-Pack

This is my second purchase. Works great and no battery wories for 10 years

Shipping was great, easy to install.

If I could give these no stars I would. I purchased 2 of these in Feb to replace some old wired smoke detectors. Install was easy. The trouble came in Sept when one of them started to malfunction and give an alarm all the time when there was no smoke or heavy fumes. Nothing. Also it was not a CO alarm but a smoke. At all hours of the day and night. I finally got so sick of it that I pulled it off the ceiling and wrapped it in a blanket as my poor dog was shaking violently every time it went off. Put it back up a week later. Same problem. So I tossed it. Now here we are in Nov and the other one I bough is doing the same thing. Going off for no reason. Even wrapped in a blanket it was still going off. So I put it out on the porch. With fresh air and everything. And it continued to go off sitting outside intermittently for 2 more days before it too went in the trash. We are of course outside the return window. So I spent $80 to not have any smoke detectors in the house and will have to shell out more money again to buy another brand. These werent old. Both had been up less then 9 months when they malfunctioned. Dont waste your money on these unless you like your pets being traumatized at 2am when the thing randomly goes off for no reason and wont stop.

Since I put it in, I've had no trouble. It works fine. hear on time.

after one year, almost to the day, it started chirping 3 times which indicates a bad unit. So, blew it out with my air compressor and the chirping seems to have stopped. waiting to see what happens.