Cane Creek Shims enable you to fit any 25.4mm or  27.2mm seatpost to a larger diameter seat tube 

Construction:

A custom-machined aluminum sleeve, sized internally to mate any 25.4 or 27.2mm seatpost to a larger-diameter seat tube 

Who rides it:

The shim, compatible with all conventional seat pillars (including the Thudbuster), makes a perfect frame/seatpost interface attainable 

Specs:

Materials: 7005 Aluminium 

Weight: 12-48g, depending on size

Size: Diameter of 25.4 to fit  Outer Diameter of 26.8, 27.0, 27.2 and 27.2 to fit Outer Diameter of 28.6, 29.4, 30.0, 30.2, 30.6, 30.8, 30.9, 31.4, 31.6, 31.8 

Colour: Black