Staubli SAB4-G Series 4 mm Panel Sockets. SAB4-G series 4 mm panel sockets with a rigid insulation sleeve for surface mounting into predrilled panels. These sockets have a 600 V, CAT II / 32 A rating and are made from machined brass. The sockets are terminated with an M4 threaded bolt and are designed to mate with spring loaded 4 mm diameter plugs which also have a rigid insulation sleeve. The insulation sleeves of these SAB4-G series 4 mm sockets are colour coded for ease of identification. Features and Benefits. 600 V, CAT II / 32 A rating Rigid, colour coded insulation M4 connection bolt