Product electric voltage contain AC110V, AC220V, DC24V, DC12V etc. electric voltage, product contain various colors can be provided as choice, adopt the LED give out light the life span can attain 100,000 hours, adopting the various fixing the way:1.The magnetic iron fixs 2.Three screws fixs 3.The single a M26 screw fixs, can also take moreover every kind of report to the police orotundly a test can attain the 90 DBs( decibel) is above.Product diameter 100 MM.