Details: specification: Material:6601 Aluminum alloy Diamter:25.4 mm 27.2 mm 28.6 mm 31.6 mm Length:350 mm Wall Thickness:3 mm Color:Black Weight:About 170 g Package Included: 1 x Bike Seatpost Characteristic 1.The material of this seatpost is a high strength aluminum alloy 6061,manufactured by integral forging. 2.Easy Installation: It is easy to install the saddle on this seat post. 3.With the general specification of the dimensions of the clamp,it fits most of the saddles (the four sizes commonly used for you). 4. There is a safety line logo, adjustment is easy. 5. By raising the saddle height, a forward leaning riding position is born, even if the air resistance (drag) is reduced.