Features: operation and excellent performance. Belt drive design, effectively reduce noise. Easy to use stable performance. Compact in size, easy to carry and easy to install, high strength, and not easy to deformation or damage, a great upgrade accessory to improve your RC car performance. Specification: size: 3.17mm Color: As Shown Material: plastic+metal Suit for:1/10 RC Crawler Car Axial SCX10 Wraith 3.17/5.0mm Motor Gear. Installation Steps: 1. Use the metal disc of the Gearbox to put it in; 2. Both and small friction plates are glued with double-sided tape; 3. The groove on the pulley is pasted with a friction plate of corresponding size; 4. Put the bearing in the middle; 5. Install metal discs, non- springs, and nuts; 6. Install the two gears closer to fit the belt, and then adjust the distance between the gears to tighten the belt. Package Contents: 1 Set x Belt Drive Gears Set for RC car Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.