Features: * Made of plastic material, good toughness, long service life and practical * Prevents the chain from falling behind the flywheel and reduces deposits on the flywheel * Easy to install and use * Chain protector for mountain bike disc brake box hubs and derailleur cassettes * Before purchasing, please check whether the size of our products is suitable for your bicycle Specifications: *Product Name: Flywheel Guard *Material: plastic *Size: approx. Diameter: 138mm/5.4inch Inner diameter: 41.3mm/1.6inch *Color: black *Weight: about 11g Package Content: 1 x Flywheel Guard Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data(1cm=0.39inch) Made of plastic material, good toughness, long service life and practical Prevents the chain from falling behind the flywheel and reduces deposits on the flywheel Easy to install and use Chain protector for mountain bike disc brake box hubs and derailleur cassettes Before purchasing, please check whether the size of our products is suitable for your bicycle