This Columba RJ26A 12-inch extended alloy seat post was created for people who are taller than 5'9" but shorter than 6'1".
This seat post is 27.2mm in diameter, and 12 inch (300 mm) in length. It is made of aluminum alloy and designed specifically for RJ26A bike. This seat post is NOT for the SP26S bike.
To install your new seat post, just take off the original, shorter seat post on your Columba RJ26A folding bike and replace it with the new, longer seat post. Then, push the seat post all the way into the frame socket until you can no longer see the minimum insertion mark. Make sure the quick-release handle is in a locked position on the bike frame. Enjoy your ride!