Features1Compatibility: The seat tube gauge is suitable for seatpost ranging from 25mm to 31.8mm in size, providing versatility and compatibility with a range of different seat posts. 2Convenient Sizing: Seat tube gauge can easily and quickly measure the width of the seat tube, allowing for easy selection of the appropriate seat rod for a fit. 3 Material: Constructed from materials, the seat tube gauge is not only sturdy and long lasting but also lightweight, making it easy to handle and use during measurements. 4Precision Machining: Seatpost measuring tool is precisely machined to ensure accurate and reliable measurements, providing high accuracy of their sizing decisions for seat rods. 5Easy to Use: Seat tube gauge is designed for ease of use, enabling quick measurement of seat rod sizes or frame seat tube bores. Simply need to place the gauge inside the seat tube.SpecificationItem Type: SeatTubeSeatpostGaugeMaterial: Aluminum AlloyPackage List1 xSeatTubeSeatpostGauge