Functional: Bike single speed conversion kit can change multi speed bike into single speed bike.Premium and Reliable: Bike chain tensioner and kit packages are made of high quality aluminum alloy and stainless steel material, which is wear resistant, rust resistant, sturdy, and durable.High Performance: Ensures perfect tension for your chain to make you pedal with less effort, suitable for long time outdoor riding.Easy Installation: This chain tensioner kit mounts right onto a mountain bike derailleur hanger to provide a simple, effective, and adjustable way to tension a single speed system.Package Contains: 1 Chain Tensioner, 5 Single Speed Spacer with Lock Ring, 2 Wrench with Spacers, 1 Single Speed Cassette, and 1 Torque Regulator.Specification:Material: Aluminum Alloy, Stainless SteelPackage Size16cmx11cmx5cm/6.30inchx4.33inchx1.97inchPackage Includes:1 Chain Tensioner5 Single Speed Spacer with Lock Ring2 Wrench with Spacers1 Single Speed Cassette1 Torque RegulatorNote:1. Please allow slightly error due to manual measurement.2. Due to the difference between different monitors, the picture may not reflect the actual color of the item.3. Wish you a wonderful on line shopping!