1, alarm sound 100db 2,12Vdc/24Vdc 3, easy to install 4, smart design Strobe light with 100db alarm soundDC16-30V Powered Sound Tone can be selected:I-Ambulance, II-Police Car, III- Fire-engine Long life of Strobe:Minimum 40000 times Strobe flash rate: 1 flash per second Loud alarm sound: Minimum 100dB Suitable for the majority of conventional fire alarm systems