The Titan Tools 51739 offset oxygen Sensor socket is designed for removing and installing oxygen sensors and vacuum switches in most foreign and domestic vehicles. It fits 7/8" or 22mm sensors and has a cut-away side for Sensor wire clearance. The offset design provides extra leverage for easier removal in tight, hard to reach areas. This offset O2 Sensor socket is built to work with a 3/8" square drive ratchet or breaker bar.