loop connection

four-wire connection direct from Wanlin Fire Protection — 12-year factory experience, WL-SFP500 smart fire detector certified CE/EN14604/EN54/UL217/UL268/FCC. Key specs: Multi-Sensor Fusion (Smoke + Heat + CO) + AI Machine Learning Algorithm + 4G LTE + WiFi Dual Communication + Edge Computing, 4G LTE Cat.1 + WiFi + AI Cloud Platform + Smart Push + Predictive···