Description: There is no doubt that the bike seat tube can bring a comfortable riding experience because it can reduce the pressure on the legs effectively because the design of ergonomic height. Featuring excellent shock resistance, which it has good use feeling. And it has delicate appearance and good stability because its high hardness and smooth line design. It is made from carbon fiber and aluminum alloy, is durable to use. There are two sizes of the product to choose from. Our bike seat tube is suitable for road bikes, mountain bikes, folding bikes, etc.. Item Name: Bike Seat Tube Material: Aluminum Alloy,Carbon Fiber Features: Anti-rust, Smooth Surface, Perfectly Fitment Color: Matte Black Size: 350mm/400mm Specifications: 1 (25.4mm), 2 (27.2mm), 3 (30.8mm), 4 (31.6mm) Size Details: Bike Seat Tube Length: 350mm/13.78" (Approx.) Bike Seat Tube Length: 400mm/15.75" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Reminder: There are four specifications for the outer diameter of the seat tube: 25.4/27.2/30.8/31.6mm. Please make sure to figure out which type of seat tube your frame uses before purchasing. Package Includes: 1 x Bike Seat Tube