12 point deep well thin wall mirror polished chrome vanadium socket with dual grease rings. Oversized callout forged into socket wall for quick and easy size identification, and will not rub off, wear out or rust with use. Socket center hole punched for added work depth. Chamfered opening for easier mating to fasteners. Z-Drive hex design contacts flat walls of fasteners for stronger grip. Meets or exceeds ANSI standards. Lifetime warranty.