This is a optional Tamiya Lightweight Center Universal Shaft Set, and is intended for use with the Tamiya TRF801Xt. The lightweight of these Universal Shafts is achieved by reducing the shaft diameter from 4.2mm to 3.4mm. The weight of the standard shafts (front 28g rear 32g) compared to the lightweight shafts (front 24g rear 27g) which equals a weight saving of almost 10g.
Eliminating weight from the drive train of your vehicle is often the first upgrade recommended by pro racers, regardless of the brand of car you drive. Reduced rotating mass will aid in smoother acceleration, faster spool up, shorter braking distances, and will help you achieve faster lap times on the track.