SSA will sound a loud audible alarm 110dB and flash a strobe lights when activated by an alarm or Z-wave network command. Intended for use inside the home with a Z-wave Home Automation & Security network as a primary and/or auxiliary alarm. Plug into a wall outlet or use with 9V battery only. Also acts as a signal repeater. Tamper proof feature uses 9V battery backup to sound alarm if main power is disconnected.