electric bell Features:
1) Alarm of easy combustion causticity air or conductive dust
2) The surrounding temperature does not exceed 40°C
3) Bear to press: 1,500V, 50 times/a minute
4) Electric resistance: shouldn't be small than 10Ω
5) Settle the electric voltage ±10%
6) Switch every 5 minutes
7) Work time: not longer than 5 minutes
8) Uninstall the bell cover to move absolutely