BRK 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 65,000 security codes and 3 channel frequency hopping.