Feature: 1. Safer Running: Equipped with this ball bearing, your RC car will have more stable and safe running performance on the road. 2. Pretty Design: Better safety together with pretty appearance will better complement you RC car, very simple but practical. 3. Good Material: Adopting premium steel material, all the 10pcs bearing has good durability with wearing and long term use. 4. RC Screw Part: Suits perfectly for 1/10 ZD Racing 10421-S, the ball bearing enables small friction and higher speed as well. 5. Standard Size: Thanks to the standard size, the installation and replacement of the 10 x 5 x 4mm ball bearing is very easy. Specification: Item Type: RC Ball Bearing Type: RC Accessories Material: Steel Colour: Silver Product Size: Approx. 10 x 5 x 4mm / 0.39 x 0.2 x 0.16in Application: For 1/10 RC car, such as for ZD Racing 10421-S, etc. . Package List: 10 x RC Ball Bearing Note: 1. Please allow a small error of 1‑3cm in the manual measurement.2. Due to the inconsistent monitor calibration, the colour of the item shown in the photo may be slightly different from the actual object.