Air locker locking differentials allow you to tackle the toughest terrain. The world's premier traction aid, ARB air lockers keep you moving in all conditions. With ARB you get a fully selectable on/off operation. This "Selectable" Type of locker really is designed to offer the BEST of BOTH worlds. These "worlds" include fully LOCKED and fully UN-LOCKED with the flip of a switch. When we say "Locked" we are speaking about locking the internal spider gears inside the differential so that both wheels/tires get equal amounts of power/traction at all times with ZERO slipping. This is the best choice for someone who wants a hardcore "daily driver" outfitted with the absolute best quality locker without having to make any sacrifices to his or her on-road drive-ability. Air is reliable and safe and this is what makes the ARB the locker of choice around the world.