Sirena interior wireless AX PRO Hikvision DS-PS1-I-WE( Red indicator ) supporting 868MHz two-way communication via Cam-X protocol,multiple alarm sounds, strobe light indication, is used forinstant alerting when alarm triggered, Buzzer Decibel: 90 to 110 dB,Quiescent current: 25 uA, Max current: 1.6 A, Voltage: 3 V, Battery life span Up to 2 years (standby time)