Product Overview: A 4X4 And Traction Go Hand-In-Hand; However, Standard (Open) Differentials Allow Each Wheel To Turn Independently To Eliminate Binding In Turns. Off-Road This Becomes A Problem As Engine Power Takes The Path Of Least Resistance--To The Wheel With Little Or No Traction. Limited Slip Differentials Offer Some Improvement, But Too Often The Slipping Is Not "Limited" Enough To Maintain Forward Progress. Automatic Locking Differentials Also Have Disadvantages; Noisy When Disengaging, They Can Also Upset On-Highway Driving Characteristics.Created To Provide Traction On Demand, Without Sacrificing Highway Driving Performance, Arb Air Locker Differentials Employ A 12 V Arb Air Compressor (Sold Separately) To Pneumatically Operate A Solid And Durable Locking Mechanism Inside The Differential. When Activated, The Air Locker Prevents The Differential Gears From Rotating And 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 Just Like A Conventional Open Differential.Product Info:Arb Airlocker 35 Spl Compatible With Sterling/Corp Compatible With Fo-Rd 10.25&10.5In S/Nquantity: Sold As A Kit.Part Type: Differential Carriersproduct Line: Arb Air Locker Differentialscarrier Material: Nodular Irondifferential Case Design Type: Compatible With Fo-Rd 10.25/10.50 Inchaftermarket Carrier Style: Air Lockeraxle Shaft Spline Quantity: 35Manufacturer Part Number:Part Number: Rd140Guarantees And Warranties:30-Day Satisfaction Guaranteesee Manufacturer's Website For Most Accurate Warranty Information.