this button is a kind of specialism conflagration set used for artificial start in the system of self-motion conflageration.eyewitness only need to broke face-plate glass of conflagration button in strength.then can make conflagration signal sending to the controller and give out the part of conflagration.at one time,can use to start conflagration equipment of message indicator,alarm bells straightly,etc.. technology: Working Voltage:220VAC 50HZ 24VDC Max.Current:5A 220V 50HZ 8A 24VDC Contact Resistance:≤0.1Ω Working Conditions: Temp.Range :-10℃ to 50℃ Max.relative humidity:≤93?%