On/off battery master switch. Contour lock system allows it to be a stand alone unit or locked together with other switches. Features a control knob which cannot be removed whilst in the on or off position, however can be removed by switching to an anti-theft position. Interchangeable labelling system on the control knob. Switches come standard with the battery symbol label. Removable rear cover and side plates on 4 sides. Surface mount or recess mount in a 52mm hole. Screw holes 5mm roundhead. Ignition protected. Non-corrosive construction.