 FW2-H & FW4-H Models with built-in thermal heat sensor

 for more accurately detecting a wide range of fires (135F Heat Detector)

 2 or 4 Wire Models

 Highly Stable Operation, RF/Transient Protection

 Two built-in power/sensitivity supervision/alarm LEDˇs

 Non-directional Smoke Chamber

 Vandal Resistant Security Locking Feature

 Built-in magnetic go/no go detector test feature

 Removable smoke labyrinth for cleaning or replacement

 Automatic Sensitivity window verification function meets outlined equirements in NFPA 72, Chapter 7, Inspection, Testing and Maintenance