Focus wireless alarm system compatible smoke detector MD-2100R
It works with ST-IVB, FC-300, FC-7664, PB-500R, PB-403R ST-IIIB, ST-IV, ST-V, ST-III, ST-II, FC-7564, FC-7448 alarm panel and wireless alarm accessory.

Functions and Specification:
1.Photoelectric infrared LED 
2.Ceiling mounted and send status signal every 15s or 65s.
3.It is in comply with UL217, 3.2% /feet.
4.Automatically send low power signal and send resetting signal. 
5.Frequency:433MHz
6.Transmitting distance:50m
7.Can be independent usage with light and sound on-spot alarm or wired to alarm panel or wireless alarm output.