The INT400 sounder is used for notification of an alarm condition as generated within an intruder, hold-up or other alarm system. 110dB(A) siren output. 12V dc voltage operation. Polycarbonate cover and backplate. 2 way tamper protection: cover, rear. Negative Tamper return and Ring Line Monitoring (with compatible panel). Hold-off supply failure detection. Selectable sound auto cut-off timer. Full SAB using internal battery (INT400S).