7PC OXYGEN SENSOR SWITCH OIL SENDING UNIT SOCKETS REMOVAL AIR PRESSURE VACUUM * 1/2'' DR x 29mm (6 point) pressure/vacuum switch socket with slot. Allows the removal of oil pressure sending units on late 1980 and mid 1990 GM vehicles Designed to be used with 1/2" drive tool. * 3/8'' DR x 7/8'' or 22mm (6 point) vacuum switch socket with slot. 1/2'' DR x 27mm (12 point) oil pressure sending unit socket.