Giant Contact SL Aero Stem and Cover is a lightweight 3D forged 2014 aluminum construction stem with 31.8mm clamp diameter to fit OD2 steerers (shim available for 28.6mm). Aero design featured on Propel Disc models, comes supplied with cover to tidy up the front end cables and increase aerodynamic performance. FEATURES Material: 3D forged 2014 aluminium Length: 80mm / 90mm / 100mm / 110mm / 120mm Fit: 31.8mm (OD2), shim 28.6mm (1'?") steerer tube Extra: Titanium hardware Weight: 290g for 100mm including cover