3D forged and CNC machined AL6066 w/ alloy headDirectional butting of the Energy SBS SB20 seatposts 6066 aluminium shaft gives it thicker walls fore and aft for stiffness and thinner walls at the sides to cut weightClamp fits 7mm standard rails and 7x9mm oval railsWE and Di2 compatible27.2mm350mmBlkAly20mm275gUPC/EAN/GTIN: 840031009005