Suitable for bikes with Shimano's electronic Di2 groupset, either MTB or road. A very tidy solution and light solution for mounting the internal battery cleanly and safely in the seatpost.
It uses the similar sticky material found on the Tune Gum Gum headset expander, just by tightening the bolts compresses the silicone material pressing it outwards and gripping onto the inside of your seat post - it's complete safe for light carbon posts. Easy to install and easy to remove.
Available in 2 sizes ID26-8 - 27.6 (27.2mm) and ID28mm-30mm (suit 30.9 and 31.6mm)