feature: Made of aluminum alloy material, lightweight and, it can be used for a long time. Fully machined, non-slip, easy to install and remove Suitable for bikes, mountain bikes, road bikes and more. It can be used as a set of large-diameter For seatposts and small-diameter For seatposts. CNC machining anodized Specification: Product Name: For Seat Tube Reducer Material: aluminum alloy Color：black Packing size: 80*60*60mm Package Contents: Seat tube reducing sleeve*1 Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data. Features: MTB Bike Reducer Adapter Suitable for Large and Small Diameter For Seatposts Material: light weight, good strength and well temperature resistance, good impact resistance Appearance and performance: automatic cutting, smooth edge, fit most of the road bicycles, delicate texture. Compatibility: smooth surface and exquisite workmanship, fit most of the bicycles. Easy Installation: Brand new and high quality, easy to install.