The original Model 100 series Smith & Wesson handcuffs are among the best selling police handcuffs in the world. They are fabricated from the finest quality carbon steel, manufactured with heat treated internal lockworks, feature 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.