The 17.5 Pucks system for the TLR 22T 4.0 / 22SCT 3.0! MIP Pucks are a MUST HAVE for your TLR 22 Series Kit Vehicles! MIP’s all new Pucks Drive system is an aluminum based drivetrain system which includes a 2-piece Alum. Outdrive Cup & Alum. Outdrive Hub, 2 Bi-metal bones, and the replaceable plastic orange wear Pucks that take the place of the inferior steel pins. This combination greatly increases the longevity of the drivetrain and most importantly decreases the drivetrains overall rotating mass by a whopping 50%! The decrease in weight directly results in quicker acceleration, deceleration, and lower motor temps!