MIP Roller Pucks reduce upwards of 25% of your rotating mass in one convenient shot. This weight reduction is achieved by MIP's Bi-metal outdrive design that offers the weight savings of aluminum (diff ring disk) coupled with the ultimate wear of steal (outdrives) needed for the MIP Roller Pucks. The Bi-metal diff also transfers the bone design over to that of a CVA. This means that you can use your normal TLR axle with an MIP shiny bone to keep the current binding characteristics you are used to. The diff balls are upgraded to tungsten carbide for the ultimate in wear and efficiency. Overall, this race proven design lightens up your drivetrain's rotating mass, which means quicker acceleration, less motor fade, and now you can keep your drivetrain fresh with replaceable Roller Pucks!