bus based smoke detector

non-polar two-wire bus direct from Wanlin Fire Protection — 12-year factory experience, WL-SFP600 smart fire detector certified UL 217/UL 268/UL 2034/UL 864/CE/EN14604/EN54/FCC. Key specs: Fixed Temperature + Rate-of-Rise Heat Sensing + LoRaWAN Long Range + Ultra-Low Power + Dual Communication, LoRaWAN + IoT Gateway + Cloud Platform + Long Range (up to 15km···