To convert a unicycle (or bike) that normally fits a 25.4 seatpost to fit a 22.2 seatpost.
Material: aluminium
ID= 22.2mm
OD= 25.3mm
Length = 40mm Weight = 10g
Note: When installing don't forget to apply a little grease to both sides of the shim as this helps prevent binding that can damage both the shim and seatpost.