Material: Stainless steel.
Note: Includes cage, two rings, lock, keys, and allen wrench.
Strategically placed within the cage are 10 screw spikes, which can be taken out and moved around according to your desires. Use the allen wrench to screw them in or out, driving the sharp tips into their flesh as far as you want.
Measurements: Cage portion is 1.75 inches in length, with a 1.3 inch diameter opening. Rings have an inner diameter of 1.75 inches and 1.95 inches.