These handcuffs feature a double-locking mechanism that allows the user to lock the cuffs in two different positions, providing additional security. The double-lock also prevents over-tightening, reducing the risk of injury. The Smith & Wesson model 100 handcuffs are designed to be lightweight yet strong, offering maximum security and reliability. They are designed to fit all wrist sizes, and the keyhole is located on the top of the cuff for easy access.