Smooth Steering Wheel Spinner Knob Fits steering wheel sizes .5" - 1.75" Diameter Comes with 4 sets of screw lenghts: 30mm, 35mm, 40mm, 45mm Fits Steering Wheels Universally - Forklifts, Mowers, Tractors, Boats, ETC Easy to install Steering Wheel Spinner Knob - all necessacy tools and hardware included Installation Instructions - Attach Steering Wheel Spinner to the steering wheel, then add screws from the bottom piece to the top piece. Tighten until firm on steering wheel Deluxe, Smooth, Effortless Spinning