Description: 【Feature】: This Bike Chain Tensioner offers great and smooth shifting, easily adapting to various road conditions. Whether you're a beginner or an experienced cyclist, it is easy to use and handle 【Material】: Made of aluminum alloy, this Rear Derailleur Chain Tensioner is reliable, stable, and reliable. It can maintain stable shifting even on rugged terrains 【Versatile Compatibility】: It can also be paired with different guide wheels, offering flexibility and adaptability to various bike setups. Please pay attention to the installation method of this chain stabilizer to ensure optimal performance and longevity 【Aesthetic Design】: The Chain Tensioner with a sleek and elegant look that harmonizes with your bike's overall design. Nice accessory for cycling lovers 【Feature】: The Bicycle Chain Tensioner is lightweight, portable and compact, easy to install and use. Hole Diameter 10 mm/0.39 inch Specification: Material: Aluminum Alloy Size Chart: Hole Diameter 10mm/0.39inch; Package Size 11cmx5.5cmx4.5cm/4.33inchx2.17inchx1.77inch Package Includes:1 Bike Chain Tensioner Note: Please allow slightly errors 1-2cm differences due to manual measurement.