Permanently mark master or restricted keys with HPC’s Specialty Locksmith Stamps. Let other locksmiths and key duplicators know it is a special-purpose key and is part of a restricted system. The stamps are made of heavy-duty steel stock, hardened and zinc plated for years of trouble-free service.

They measure 3.25 x .625 x .375 inches (8.25 x 1.6 x 1cm). The characters are approximately 0.1 inch (2.5mm)