Luxury Stainless Steel Neck and Wrist Restraints with Locks. The maximal inside diameter of the wrist-cuffs is 5.6 cm. The inside diameter of the neck collar is 12.0 cm, the rod diameter (thickness) is 1.1 cm. I HAVE TO SAY THAT METAL RESTRAINTS ARE JUST A CUT ABOVE LEATHER AS YOU KNOW THERE IS TRULY NO ESCAPE.
