Offers a number of unique features the highlight being the patented Contour Locking System allowing it to be a stand alone unit or locked together with other switches. - Features a control knob which cannot be removed while in the ON or OFF position however can be removed by switching to an counter-clockwise 45deg position. The control knob also features an interchangeable labelling system allowing a full range of applications - Removable side plates on 4 sides for access of up to 1/0 cables plus a rear cover insulating the rear terminals against any short circuits. This ensures the switch meets ABYC requirements. - Can be either surface or recess mounted by cutting a 52mm (2.1") hole.