TAODAN 4PCS Bicycle Flywheel Guard Folding Bike Plastic Transparent Chain Cover for Disc Brake Hub and Variable Speed Flywheel System Riding Scenarios

["The freewheel guard is made of engineering-grade plastic in a single-piece construction, offering excellent toughness and resistance to cracking or breakage, with a smooth, wear-resistant surface.","Outer diameter 138mm, inner diameter 37mm, specifically designed for 28T to 34T cassette sprockets, fits the rear hub perfectly, and remains stable and secure after installation.","Made of semi-transparent material, it does not affect the original visual appearance of the wheel set after installation, maintaining a clean and attractive bike appearance while providing protection.","Effectively prevents the chain from falling off the inner side of the cassette while blocking dirt and sand from entering the cassette area, reducing wear and tear.","Suitable for disc brake hubs and derailleur cassette systems, compatible with various bike types including mountain bikes, road bikes, and folding bikes, meeting protection needs for different riding scenarios."]