Good product, easy to use and installation (2 screws each). Attention, it is important to read the manual (15 pages written small not very big, but in French, which is rare!), Which allowed us to install the devices in the right places and not where we foresaw. Also important to read all the instructions and especially on battery replacement (do not panic if the detector is flashing, it is normal, it will beep to indicate battery change). The screws and plugs are provided, each device was installed in less than 5 minutes is very convincing! Flawless test, and 15j, no false alarm. See with time. Note that the included batteries have a date of use indicated at the end of 2013 (for proceeds received in February 2015 ...) but work.
