<ul><li>ARRMA F/R Diff Set GP4 5mm 29mm Open Diff Case 80K, ARA311199</li></ul> This Front or Rear Open Spiral Cut Diff Set provides a pre-assembled unit for your ARRMA vehicle Features Factory assembled and filled with 80k cSt silicone oil for fast and efficient servicing Tough steel internal gears for long-lasting durability in all conditions Traditional differential assembly for open differential action Strong composite diff case with integrated steel insert for durability 43T GP4 spiral 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 Open differential favored on rear axle Includes 1 x Factory Assembled Open Front or Rear Diff, GP4 43T Spiral Cut Gear and 80k cSt Silicone Oil