The Problem Solvers Seatpost Shim is what you need when your seatpost is a little too small-diameter to fit tightly into your frame. It's made of light and durable aluminum and has a lip on the top so it won't slide down inside the frame during installation.
|2.0mm shim, 27.2 seatpost to 29.2 frame||708752009899||ST0220||20M248935562|
|4.4mm shim, 27.2 seatpost to 31.6 frame||708752012875||ST0244||44M241792806|
|3.2mm shim, 25.4 seatpost to 28.6 frame||708752024397||ST0532||32M244726436|