Feature: 1. EXCELLENT PROTECTION: Keep the brake disc from scratches and friction, prevents oil or dust from contaminating the brake disc, perfect for everyday riding. 2. ALUMINUM ALLOY MATERIAL: The bike chain protector is made of high quality aluminum alloy material, which is strong and durable and can be used for a long time. 3. HIGH PERFORMANCE: The bike sprockets cranksets guard is capable of replacing old or damaged bike accessories to dramatically improve performance. 4. SIMPLE OPERATION: The chain wheel crankset cover is easy to install and beautiful, bringing you a more comfortable riding experience. 5. FINE WORKMANSHIP: The bike chain guard protector has fine workmanship. No difficult techniques are required, even if you are using it for the first time. Specification: Item Type: Bike Sprockets Cranksets Guard Material: Aluminum Alloy BCD: Approx. 104mm/4.1in Specifications: 38T-42T Package List: 1 x Bike Sprockets Cranksets Guard Note: Manual measurement, please allow slight error