The Smith & Wesson Model 1 Universal Handcuffs feature a push pin double lock design in a satin nickel finish. The Model 1 cuffs open 12% larger for big wrists and close 11% smaller for thin wrists for better security. All 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.