Product description:

Power supplied DC9V battery and back-up source 
110V-240V AC mains power supply 
Supply voltage DC12 to 30 volts

Interconnect up to alarms 
Photoelectric sensor 
Red LED mains indicator light to confirm mains power supply 
Green LED mains indicator light to confirm mains power supply 
Unique" battery missing" lockout 
Hush feature to silence nuisance alarms 
Low battery alarm 
Test button 
Relay contacts-volt free with Normally Open and Normally Closed 
Options and rated to 24 volts /1amp resistive 
High sensitivity 
Alarm supplied with "connector plug" for ease of installation