The Sonic bracket offers an extensive fit range, low weight and easy adjustment along with minimal frontal area. Combining this with the Ergo armrest creates an aerobar that will aid most riders in optimizing their position for both speed and comfort. The 52A is one of the newest versions of our reliable aluminum extension range. FEATURES: Performance: The Sonic/Ergo is designed to present minimal frontal area to create as little aerodynamic drag as possible. The main purpose of an aerobar is, of course, to get the rider into a fast position despite a fairly minimalist appearance the Sonic/Ergo offers a comprehensive fit range for exactly this purpose. Fit Data: The 52a extensions have a 52° for the grip. The rider can choose whether to hold high for the shrugged position or low for a more open, head up position. Armrest Offset: -70mm to -17.5mm in 7.5mm steps Armrest Width: 124mm to 290mm in 18.5mm steps ( With Extensions at 100mm) Armrest Stack: 60mm (no riser kit) to 130mm in 5mm increments (With aftermarket Riser Kit) SPECS: Bracket: Sonic Clamp Diameter: 31.8mm or (26.0 with Shim Kit - Shim Kit is sold separately) Armrest: Ergo / 10mm Pads Armrest Width: 124mm to 290mm in 18.5mm steps (with Extensions at 100mm) Armrest Offset: -70mm to -17.5mm in 7.5mm steps Armrest Stack: The minimum is 60mm and the bracket is compatible with our existing risers which add up to 130mm stack with (70mm of spacers added) Construction: 6061-T6 aluminum, pre-drilled for bar-end shifter cable routing Extension Length: 400mm Extension Angle: 52 Degrees Extension Rise: 87mm (bottom to top) Extension Offset: 15mm total Outer Diameter: 22.2mm Inner Diameter: 19.2mm Shifter Compatibility: Electronic or Mechanical Color: Anodized Matte Black Weight: 564g Bar Clamp: 6Nm ( 53 inlbf) Extension Clamp: 6 Nm (53 inlbf) Armrest Bolts: 4.7Nm (42 inlbf) Bracket: 234g Armrest: 130g Extensions: 222g Total: 586g