fire alarm battery backup

Wanlin Fire - China source manufacturer for fire alarm battery backup. Featured model WL-TH-SD (Photoelectric Smoke Detector): Dual-sensor: photoelectric + 57 deg C thermal backup; EN54-7 Class A3, alarm at 0.13-0.17 dB/m obscuration; Built-in 88 dB at 3 m sounder + NO/NC relay contact; -10 to +55 deg C, 0-95% RH (tropical humidity rated). Full lineup: smoke···