GearWrench 41720 Sensor and Sending Socket 8pc Set GearWrench 41720 Sensor and Sending Socket 8pc Set includes a blow mold case for storage and organization, a 3/8” drive 7/8”(22mm) low profile offset socket for O2 sensor unit, and 3/8” drive 7/8”slotted socket for PVS, TVS and O2 sending units.