ARB 4x4 Accessories Competition Edition Air Locker Ford 9 Inch , Rear 35 Spline (All ratios) RD99CE 290% increased case strength; Deeper clutch gear engagement; Built to handle misalignment in steeply offset axle housings; Improved internal oiling; Ring gear bolt locking mechanism; Designed to integrate with load-bolt equipped drop-outs; Pre-loaded internal gears;Forged gear set; Carrier bearings included in installation kit; 5 Year Warranty; Requires Aftermarket Carrier Case With 3.250 Bore; Requires Aftermarket Axle Shafts ARB 4x4 Accessories ARB Ford 9 Inch 35 Spline Competition Air Locking Differential - RD99CE RD99CE Differentials