Application:brand new quality assured idler sprocket, the sprocket connects to the swingarm; then the chain runs in alignment on it, the drive chain roller can also be retrofitted to petrol-powered bicycles. Professional Manufacturing: The inner diameter of the chain tensioner idler pulley is 10mm, with fine workmanship and stable performance. It conforms to standard specifications and is manufactured under strict adherence to factory quality control conditions. All components meet strict production requirements. High-quality materials: The drive pinion is made of high-quality nylon, with high hardness, stable dimensions, not afraid of wind and rain, crack resistance, color fastness and wear resistance. High quality products, quality is guaranteed. longer life. Easy to assemble: Equipped with ready-to-use heavy-duty bearings, quick assembly, find the right installation location, simple operation can be assembled successfully. The installation can be done in a short time and hardly any mechanical knowledge is required. Specifications: Inner Diameter: Approx. 10mm / 0.39 Outside Diameter: 3.5cm / 1.38 Total Length: 3.3cm / 1.3 Package Weight: Approx. 55g Color:blue Package Included: 1 x Drive Chain Roller Note: 1. Please allow 1-3mm error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. 3. Please be carefully check the parts appearance, size, shape and then compare your original goods for compatibility before ordering, Thank you.