Features: 1. This Single Speed tensioner is a product to allow single speed set up to be run on geared bikes without the expensive modification you had to do in the past. 2. This chain tensioner mounts right onto your derailleur hanger to provide a simple, effective and adjustable way to tension a single speed system. 3. With reliable quality, it is your first choice. 4. This bicycle repair tool is made of high-strength aluminum alloy, which is lightweight, wear-resistant and durable. 5. If you have any questions about the product, please feel free to contact us. Notes: 1. Due to the lighting effects and shooting angles, there is a color difference in the product, please understand. 2. Due to manual measurement, there is a tolerance in the product size. Specifications: Product size: about 15*9*5cm Packing size: about 15.3*9.3*5.3cm Package List: 1* Single Speed Tensioner