DescriptionUsed for bicycle chain guide protector chain tool bicycle parts.Simple installation, no off-chain, convenient and practical.Application: 39-42mm middle tube installation.The crank is not suitable for variable speed, it is only suitable for single speed crank.Easy to install, no complicated tool required.Can perfectly protect chain from falling out.Features: Durable, Lightweight, Anti-rust.High-strength material, wear and resistance to deformation.Specification:Material: Nylon.Size: 7.2 * 5.6 * 1.5cm.Color: black.Note:There might be a bit color distortions due to different computer resolutions.There might be size errors due to different computer resolutions.Package include:1 * bicycle anti-out chain protector.