USE Seatpost Shim
The USE shim allows you to use your USE XCR Suspension Seatpost (or any seatpost that is 25.0mm) on frames that use some of the more common seat tube sizes. Shims are designed with a "top lip" to stop the shim from sliding down into the frame, and are 100mm in length. USE seatpost shims are longer than other shims on the market giving your seatpost much better support inside the frame.
Made from aluminum and available in the following sizes:
Ordered this to use with my older carbon seat post in new frame with larger seat tube. Works well.