Hi, Nate Taylor here. Please reach out to me at nate@sscycleworks.com for inquiries on parts availabilities and shipping estimates.
Strong seat posts
On this page: Strong seatposts: 27.2mm plain alloy pillar
Strong 27.2mm plain alloy seat post. Used, $20.00/each

A plain alloy post without hardware.

It is made by Strong and it is 27.2mm.
