Risers easily add height to Profile Design aerobars to dial in your fit. Achieve Optimal Positioning : Achieve optimal positioning with the Aerobar Bracket Riser Kit. Easily adds height and quickly adapts Sonic Ergo , Supersonic Ergo , Subsonic Bracket, J3 Bracket and J2 Bracket, T+ Carbon Series, T+ Aluminum Series Aerobars to fit a wide range of riding styles. Tech Specs Compatibility: Sonic Ergo (35a, 43a, 45/25a, 50a and 45ar), Supersonic Ergo (35a, 45/25a and 50a), Subsonic Bracket, J3 Bracket and J2 Bracket, T+ Carbon Series, T+ Aluminum Series Aerobars Includes: 2 risers and 4 bolts specific to the kit size Maximum Height: Kits available in 15mm (5,10 or 15mm), 20mm, 30mm, 40mm, 50mm, 60mm or 70mm Clamp Diameter: 31.8mm Weight: 10mm - 14g, 5mm - 7g Tech Guide Kit includes 2 risers and 4 bolts specific to the kit size Risers cannot be stacked