Bosch Invisible Smoke Detector 4 Wire White Kit

“Modern, ultra-low profile design / Color inserts match the surrounding decor / Smooth, easily-cleaned detector surface / Innovative retention mechanism / High reliability / Four-wire technology (six conductor wire) / Compatible with 12 VDC or 24 VDC systems / 9m spacing between detectors / Optional carbon monoxide (CO) sensor for false alarm reduction”