Made From CNC 6061 T6 Alloy Extra Lightweight Base & 7075 Alloy Lever;7075 Alloy Quick Release Lever For Easily Adjusting the Saddle Height. This Alloy Is Exceptionally Strong With Strength Similar To Steel But Lightweight;Fits Onto 31.8mm Seat Post, Tensile Strength 310MPa;Low Weight: 40g, Hardeness Vickers 100HV, Shear Strength 190MPa;6061 – T6 Alloy Is A Medium to High Strength Heat Treated & Artificially Aged Alloy. It Has Very Good Corrosion Resistance And Very Good Weldability. Extensively Used In The Aerospace & Military Industries