Its apart of the GSM kit, love it so far
This smoke detector was very easy to install. This was a replacement for my older one and it fit perfect. The cost was much better on Amazon than what it would have cost in stores.
Easy to install, and solved the problem we had with the old smoke detector going off every time we made toast or opened the oven door.
This is for our town house. It is connected with the ones on diferent levels of our home. So if alarm detects something in abasement will spark alarm on all floors.
There was a bit of trouble installing the device, as it had changed size slightly since the last one of the same model (or seemed to). Otherwise, it is working well. Delivery was prompt.