These handcuffs are made of stainless steel and are double locking. They have slotted shackles and 23 locking positions (meaning that they have 23 grooves on the cuff). The inner perimeter measures 5 3/4" to 7 7/8". These cuffs weigh 9.2 ounces. These simple handcuffs can add new dimensions to your bondage experiences.