... Voltage: DC12V, DC24V(preferred) Button movement: 0.25-0.8mm Max button movement: 1.5mm Button contacts: 1 normally ope ... : screw-thread fixing, suitable for mounting on the panel of 1.2~4mm thicknessCharacter: Landing Call Button, Up ... and Down Direction Button, Open and Close Door Button, Alarm Button, Intercom Button, etc.lighting colors selectable ...