"CTA Tools 2064 Thin Wall Oxygen Sensor Socket removes and installs 22mm Oxygen Sensors that cannot be accessed with standard sockets. 1/2-Inch square drive and 1-Inch external hex drive. OAL: 3.5-Inch / 90mm. California Prop 65 - Warning, This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm.