BRK Electron FG250B Smoke Alarm

As described

This was an exact replacement for the smoke alarm in my Four Winds 19G motorhome. Delivery was fast, trouble free.

Really cheaply made. Once it is mounted in the ceiling, it is so hard to open again, that the screws rip out. I'm sure it works, but don't try to change the battery unless you want to re-patch and paint your ceiling.