Package included: 4 x bike seatpost clamps, 1 x Hex Key
Diameter 31.8mm suitable for out diameter 27.2mm, 28.6mm bike seat post
Material: Aluminum Alloy, Hollow lever design and rust-resistant high quality retaining bolt.
Easy to install: Simply secure with a 4mm Allen (hex) head key
Fits on:MTB,mountain bike ,folding bike,track bike,fixedgear,road bike and so on