Description This is a great Chain Tensioner Adjuster because it can prevent chain slack, bikes and any single speeds bike. Used to prevent the rear wheel from slipping forward under pressure. For track, and bikes with rear entry drop-outs. Adopt reliable material, wear and durable when used. Floating pulleys and spring adjusting devices achieve perfect chain tension. Features -Color:Silver -Material:Galvanization -Size:5.10X2.50X1.00cm/2.00X0.98X0.39in -Keeping chain slack from falling and improve driving safety. Suitable for most foldable bike. -Made of reliable material, it is durable and wear resistant for long-term use. -The Chain Tensioner adjuster has mini appearance, with durable material. Convenient to use, easy to handle. -Small size, lightweight, easy to carry. Saving the hassle of manually adjusting the chain. -Bike chain adjuster tensioner fastener bolt for bike tool. sturdy and durable. Keeping chain slack from falling and improve driving safety. Suitable for most foldable bike. Made of reliable material, it is durable and wear resistant for long-term use. The Chain Tensioner adjuster has mini appearance, with durable material. Convenient to use, easy to handle. Small size, lightweight, easy to carry. Saving the hassle of manually adjusting the chain. Bike chain adjuster tensioner fastener bolt for bike tool. sturdy and durable.