The STEELMAN 42023 8-Piece Master Sensor Socket Set has the sockets to help you when removing and installing oxygen (O2) sensors, oil pressure sending units, and vacuum switches. These specialty tools are made of durable chrome molybdenum steel to help them stand up to the stresses incurred when breaking free stuck sensor modules. The 3/8-inch drive sizes include a 1-1/16-inch (27mm) oil pressure sending unit socket in regular and short access styles, one wide and one narrow slotted 7/8-inch (22mm) vacuum switch and oxygen sensor socket, and one 7/8 (22mm) low-profile offset slotted oxygen sensor socket. The 1/2-inch drive sizes include one 7/8-inch (22mm) offset slotted oxygen sensor socket and one each 1-1/16-inch (27mm) and 1-3/16-inch (29mm) oil pressure sending unit socket. The complete set comes in its own blow molded black plastic case for easy storage.