Check the listing for details. Chain Roller Pulley Tensioner 10mm Concave Type Guide Wheel Slider Black. Condition: New. Listed at 14.40 USD. Specifications:Inner Diameter: 10mm / 0.39"Outer Mid Diameter: 30mm / 1.18"End Diameter: 33mm / 1.3"Length: 28mm / 1.1"Design: Concave TypeMain Color: BlackMaterial: Nylon, Bearing SteelPackage Content: 1pcs x Chain Roller Pulley Tensioner WheelDescriptions:Nylon material is excellent in mechanical strength, wear-resistant and corrosion-resistant. The engineering plastic is widely used and is a good material for plastics to replace metals such as steel, iron and copper etc..The pulley tensioner is an external nylon roller with internal double bearings. The guide wheel is a great replacement part, quiet and wear-resistant.The chain roller wheel is suitable for go-kart, sliding door and window, irrigation equipment, and other chain drive equipment. It is also widely used for mini motorcycle, dirt bike, Atv.