‘Butt up, face down’ is probably the best way to describe this restraint set. Best enjoyed in an all-fours position, it puts the wearer’s arms behind their back, and their knees up by their chest. Easily adjustable for a custom fit and padded for comfort. Plus, the wrist cuffs can be completely detached and used separately for times when you just want wrist binding. Vital stats: Wrist cuffs adjust between 8. 5 and 11 inches in circumference. Thigh cuffs adjust between 16 and 26. 5 inches in circumference.