Products Features Billet Aluminium Lightweight Quick Release Hub (hardened) Steel, hardened Splined steel Adaptor (weldable) to suit the Quick Release Hub Annodised plated for corrosion resistance and longer life Greatly simplifies the removal of steering wheels to allow more access to the car race seat. Simple, spring mounted release button operation. 3 x Mounting cap screws supplied 2 Years Guarantee Perfect for all general forms of Motorsports. The Inside Diameter on the shaft end is 0.75 inch (3/4").