The Siren SE812 Siren will warn everybody in the building by a loud sound and a flashing light that an alarm has occurred. This product is especially suited to use in combination with other Z-Wave devices such as sensors. Warning by sound and light The SE812 Siren gives a loud sound and a flashing warning light, so everybody in the building will know immediately that an alarm has occurred. You can choose to activate the siren either by burglary alarm or by a smoke alarm or activate the siren by both alarms. It is even possible to install multiple sirens, so the alarm can be heard loudly at multiple locations. The SE812 Siren has an adjustable jumper inside, so you can choose between either a 90dB or a 100 dB volume of the siren. Powered by power supply or batteries Choose either the included batteries or a power supply to power your siren. When using batteries, the siren will give a warning when the batteries are almost empty.