50mm Length 21 OD MAX Keyed spline drive racing nuts are made from steel, CNC machined. CLEARCOAT STAINLESS finish. 12x1.50 thread (Toyota, Mazda, Hyundai) Sold in a set of 20 & one key is included. Ends are threaded to accept colored caps which may interfere with extra long studs. *Always use copper anti-sieze on studs/nuts