General Aluminum Alloy+ 3k Carbon MTB Road Bicycle Handlebar Stem, Length 60 70 80 90 100 110mm, 31.8mm Diameter Material: Aluminum Alloy+ 3k Carbon Handlebar clamp diameter: 31.8mm Fork clamp diameter: 28.6mm (1-1/8 in) Rise: 6 degrees Stem length: 80/90/100/110mm, please choose