1. Effective chain protection: The bicycle chain guide can effectively prevent the chain from falling off and moving without you having to worry about the chain falling off, extending the life of the chain and ensuring a smoother ride. 2. Design: Our chain guide is suitable for a variety of bicycle types and the chain/link rod is adjustable at multiple points. Bicycle chain guide: 20.5 cm x 20 cm/8.07 inches x 7.87 inches, conversion seat: 6.8 cm x 7 cm/2.68 inches x 2.76 inches. 3. Highquality material: The bicycle chain guide is made of highquality aluminum alloy material, lightweight, highstrength, and provides a better riding experience. 4. Easy to install: The chain guide with seat tube clamp is simple and convenient to install, the adjustment is done with a wrench, without the need to disassemble the crank.