Air locker locking differentials allow you to tackle the toughest terrain. The worlds premier traction aid, ARB air lockers keep you moving in all conditions.A complete air locker kit: replacement differential, activation switch, solenoid valve, air line and bulkhead fittings. ARB Air Locker Differential; Shaft Spline 29; Ratio 3.08 And Up; AMC Model 20; 8 7/8 in. Dia. RG; S/N....