These Special Security Handcuffs in a nickel finish feature 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.