Innovative Double Pulley Chain Tensioner, Silent and Smooth Operation: Enjoy noise-free and smooth rides with our double-spring chain guide, which minimizes chain slaps and vibrations for a quiet and enjoyable biking experience. Noise-Reducing Guide Wheel: Our silent guide wheel ensures stable, noiseless rides by minimizing chain wear and providing smooth speed transitions on any terrain. Durable Aluminum Alloy Body: Crafted from high-quality aluminum alloy, our chain tensioner is lightweight yet robust, offering exceptional stability and longevity for your mountain or folding bike. Effortless Installation: With a straightforward three-step installation process, our tensioner fits seamlessly into frames with rear tailhooks, enhancing your bike's performance without any hassle. Versatile Compatibility: Perfect for both mountain bikes and folding bikes, our rear chain guide improves stability and reduces noise, ensuring a superior riding experience across various terrains. Ultra-smooth Single-Speed Chain Tensioner with Adjustable Tension and Dual Spring Chain Guides - Noiseless Performance and Easy Installation for Dirt Bikes, BMX and Folding Bikes