The world's premier traction aid, an ARB Air Locker keep you moving in all conditions. With the flick of the switch an Air Locker gives instant lock at any moment and its super strong design allows activation at any speed allowing you to tackle the toughest terrain. The advantage of the Air Locker lies in the pneumatically operated locking system inside the differential. When activated, the Air Locker prevents the internal differential gears from rotating and therefore prevents the axle shafts from turning independently of each other. With both wheels tied directly to the rotation of the ring gear, the vehicle maintains maximum possible traction at all times. When unlocked, it operates like a conventional open differential. An Air Locker equipped vehicle can be driven in a slower, safer and more controlled manner, greatly reducing the likelihood of vehicle damage and environmental impact. Shaft: 1.37 Inch