The Fenwal Models CPD-7054 and CPD-7054D are dual chamber Ionization Smoke Detectors designed to sense both visible and invisible products of combustion. The Detectors have advanced solid-state, low-voltage, surface-mount circuitry and are designed for 2-Wire and 4-Wire installation using the appropriate Detector base. The characteristic 360-degree detector design permits smoke entry from any direction. A unique sensing chamber design permits the operation of the Models CPD-7054 and CPD-7054D in open areas with air velocities from 0 to 300 fpm and 0 to 500 fpm, respectively.