Battery Type: 3 years life- two x LR14 c-size batteries. Colour: White. Finish: ABS plastic. Material: ABS plastic. Product Technical Data: Battery Type: 3 years life- two x LR14 c-size batteries. Colour: White. Finish: ABS plastic. GTIN: 5052105528496. Material: ABS plastic. Voltage V: 3. . Product Type: Manual alarm. Voltage V: 3. Dorgard SmartSound is a wireless solution for legally holding open fire doors, automatically releasing them to close when a fire alarm sounds. SmartSound technology means the door units are not triggered by the noise of a vacuum cleaner. Wireless technology battery powered. Fire doors can be held open at any angle. Responds when alarm is activated. As soon as alarm is activated, the plunger is released and the door will close. Dorgard SmartSound product detail. Works with heavy fire doors (up to 160kg and 1600mm width) Three-year battery life. Three-year manufacturers warranty. Anti-drag technology carpet friendly. SmartSound audio filtering