Set of 2 These universal restraints are designed with a one-size-fits-most philosophy, with an adjustable interior diameter range of 51 mm (2") to 76 mm (3"). The super soft neoprene lining will keep whatever limb is locked inside comfortable and the quick-release velcro bindings remove the need to keep track of a key. Each restraint includes one D-ring that can be attached to whatever your kinky mind can imagine.