The bicycles handlebar shim converts 25. 4mm to 31. 8mm, adjustable distance to accommodate the handlebar. Increase riding safety. Made of lightweight aluminum alloy material, durable and practical, not easy to be out of shape. Corrosion- resistant and higher hardness, this increase clamp allows you to use larger diameter standard size handlebars. It is easy to install, smooth lines, smooth edges, a great accessory for your bicycles. If your bicycles handlebar diameter is smaller than the stem installation aperture, then add the handlebar conversion chip can be installed to install it. Type 25.4 To 31.8mm Handlebar Shim Size 45x31.5mm/1.77x1.24inch Material Aluminum Alloy Colour Black Part Type Handlebar Shim Brand Unbranded/Generic M.