Chicago Model X22 High Security Handcuff. These handcuffs are extremely hard to pick or shim and a standard handcuff key will not work. The teeth on the swinging bows are split down the center to accommodate an anti-shim bar that runs down the center of the slit pawl. A special double bit key is required to open. Weight 10 ounces, double locking with back of key, 2 high security keys included.