Add a flash of color to your handlebars. Alloy Bar End Plugs are precision engineered and machined using lightweight, durable 6061-T6 aluminum. They are compatible with mountain and road bike handlebars thanks to an expanding wedge that makes a secure fit for most inner bar diameters. Available in a variety of anodized color options that match Wolf Tooth headsets, stem caps, seatpost clamps, bolts, and more. Compatibility - Works with mountain and road bike handlebars. The expanding wedge makes a secure fit for most handlebar diameters. - Compatible with handlebars measuring 18mm to 21.5mm inner diameter. - Use 3mm hex tool (not included) to secure bar end plugs. Tighten until snug; DO NOT OVERTIGHTEN