1.Fire alarm bell,electric bell,fire bell,alarm bell. 2.The gong is special material to anti fire. Parameters:1.Rated Voltage:12(24)VDC2.Rated Current:20-30mA3.SPL(A)1M:≥87dB4.Material:IronDimension:Φ152mmX56mmBack of bell:Inner packing details:Supplier Assessment Report: Fire bell(Dia.152*56mm)