This special security handcuff, in a nickel finish, features a larger dimension chain and swivel for special security situations. Smith & Wesson Handcuffs are fabricated from the finest quality carbon steel. They are manufactured with heat treated internal lockworks, featuring smooth ratchets for swift cuffing and double locks to prevent tampering. All S&W handcuffs meet or exceed demanding U.S. National Institute of Justice tests for workmanship, strength, corrosion and tamper resistance