Wireless interconnect enabled alarm|Bridge unit, wireless photoelectric hardwired smoke alarm|Single button test/silence|Two silence features can silence the low battery chirp for up to eight hours or temporarily silence an unwanted nuisance alarm|Add additional OneLink alarms and hardwired alarms, links all alarms together for a complete system|Hardwired interconnect and RF interconnect reliable and secure radio frequency communication between alarms, 915 MHz frequency with 65000 security codes and 3 channel frequency hopping|Optipath 360 Technology patented technology provides 360 deg of direct access to the smoke sensor|Perfect mount allows for easy alignment of alarm|Electronically simulates smoke condition, causing the unit to alarm, press and hold test/silence button|Automatic when smoke clears|Up to 18 units, RF or hardwired (needs SA520B bridge unit), carbon monoxide and heat alarms and relays, maximum of 12 smoke alarms