This Limited Slip Center Diff Set provides a pre-assembled unit for your ARRMA vehicleFeatures:Factory assembled and filled with 100k cSt silicone oil for fast and efficient servicing - Tough steel internal gears for long-lasting durability in all conditions - Stainless steel limited slip diff plates installed for limited slip differential action - Strong composite diff case with integrated steel insert for durability - 50T 1 Module straight-cut steel main gear for increased durability under extreme loads - Metal Cross Shafts for increased efficiency - Includes rubber shielded bearings for fast and efficient fit to your vehicle - 29mm Diff Case - use 29mm Diff Case spare partsIncludes:1 x Factory Assembled Limited Slip Center Diff, 50T 1 Module Straight Cut Gear, 29mm Diff Case and 100k cSt Silicone Oil