Mountain Racing Products Tamer 27.2mm I.D. Seatpost Sizer

Allows you to securely fit your 27.2mm seat post into a bike's 30.00mm seat tube. Mountain Racing Products (map) design cycling parts with performance results in mind, planned in house, proto-typed in house, and tested on local trails in Colorado where map is based.
Quality map product
Adapts 27.2mm seat post to 30.0mm seat tube
Made in the USA