Allen Hex Head Grip Length - .550 5/16", .312 Shank Diameter, Original Style Mounting Plate measures 1" rivet to rivet Package of 10 Made in U.S.A. Black DZUS Self Ejecting Quarter Turn Fasteners are machined from 7075 billet aluminum which is stronger than mild steel, providing superior strength with a weight savings of one third that of a steel type fastener. This Dzus style fastener comes with a hex head and offers the latest modern look for your race car. Made in U.S.A.