Flat Response Photoelectric Chamber Low Profile - Only 1.8" high (with base) 2 or 4 wire base compatibility, relay bases available Highly stable operation, RF/Transient protection Low standby current, 45mA at 24VDC Two built-in power/sensitivity supervision/alarm LEDs 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 requirements in NFPA 72, Chapter 7, Inspection, Testing and Maintenance Compatible with SIJ-24 Ionization Detector Backwards compatible with Hochiki SLK and SIH detectors