1、High Quality Material: The synchronous gear is made of aluminum alloy, oxidized process, not easy to fade, not easy to rust, durable, stable transmission and high accuracy. 2、Prevent Slipping Off: 3:1 gear speed ratio and precise meshing positioning, which can effectively avoid tolerance damage, not easy to slip off during work. 3、Good Performance: The pitch of the synchronous pulley belt is 3mm, high quality rubber, high strength, good heat resistance, wear resistance, aging resistance, durable in use. 4、Easy Installation: The synchro wheel is easy to install and adjust, saving time and efficiency. Can upgrade your electric skating board. Convenient and practical. 5、Applications: Suitable for motors with a shaft diameter of 8mm such as for 5065 and 5055, suitable for PU wheels with a diameter of 70mm, 72mm, 80mm and a width of 52mm, suitable for all kinds of electric skating board DIY. Item Type: DIY Electric Skatingboard Wheel Kit Set Gross Weight: 300g / 10.6oz Material: Aluminum alloy 48T Synchronous Wheel: Pitch: 3mm / 0.1in Inner Diameter: 22mm / 0.9in Hole Distance Between 2 Holes: 15mm / 0.6in Mounting Hole: M4x6 16T Synchronous Wheel: Tooth Pitch: 3mm / 0.1in, Inner Diameter: 8mm / 0.3in Speed Ratio: 3:1 Synchronous Gear Belt Length: 246mm / 9.7in Synchronous Gear Belt Width: 11mm / 0.4in Synchronous Gear Belt Length: 243mm / 9.6in Synchronous Gear Belt Thickness: 2.4mm / 0.1in Applicable Motor: For 5065, 5055 and other motors with a shaft diameter of 8mm. 1 x 48T Gear 1 x 16T Gear 1 x Timing Pulley Belt 1 x Wrench 8 x Screw