For those who are into the more hardcore side of CBT play could find this spiked head ring suitable.

The spiked head ring is made of high quality stainless steel. The six steel spikes poke the head of the penis. As the sub goes into a state of arousal, the spikes dig deeper into the erecting cock.

Specifications: The head ring weighs .2lbs. It has an internal diameter of 1" and an external diameter of 1.25". The ring itself is 1.5" in width and 5/16" thick. An allen wrench is included to let you adjust the screws. Being able to adjust the screws also allows you to compensate for the size of the cock being placed in the ring.

A knob-ring is provided in case you want to add additional weights to the ring.