Features Perspex guard 285 x 180mm Aluminium extrusion and plastic housing has micro switch Retro fits to most Mill / Drilling machines Safety chuck guard comes complete with mounting bracket with built-in micro switch and 0.5 Metre of wiring to be connected to the electrical cabinet Just fasten the mounting bracket to the side of mill/drill head Micro switch recommended for 12V or 24V Installation is required by a licensed electrician