Quick, accurate tool for determining the inside diameter of a bikeâs seat tube taking the guesswork out of ordering a replacementMade from durable acrylic, this gauge is built to last and sized just right for shop benches, toolboxes, and trailhead tool kitsCovers 24 common seatpost sizes, from 25mm up to 34.9mm, including all the in-between sizes youâre likely to encounterCompact, lightweight, and easy to useSeatpost GaugeRed25 - 34.9mmSeatpost GaugeUPC/EAN/GTIN: 810124713492