Description: Applicable: 1. Used on 25.4mm handlebar, the handlebar becomes thicker to 31.8mm handlebar; 2. Used on 31.8mm stem, the stem becomes thinner, and 25.4mm handlebar can be installed. Made of aluminum alloy, rust proof and durable. Suitable for mountain bikes, road bikes, etc. Precision machining, which can solve the problem that the size of your frame and seat tube does not match. Easy to install, no other tools needed, provide convenience for your use. Specification: Material: Aluminum alloy Size Chart: The adapter shim length: 44mm/1.73inch Outer diameter: 31.8mm/1.25inch Inner diameter: 25.4mm/1.00inch Package Includes: 1 Piece Adapter Shim(2 Pack) Note: 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!