A cock ring is a ring that can be placed around a man's penis, usually at the base, primarily to slow the flow of blood from the erect penile tissue, thus maintaining an erection for a much longer period of time.
Cock rings can be worn around just the penis or both the penis and scrotum, or just the scrotum alone, though this is usually called a testicle cuff. Rings can be made of a variety of different materials, most commonly leather, rubber, or silicone, though nylon and metal are also used either as the main component or part of the closure.
The term cock ring is sometimes used as a synonym for a Prince Albert piercing, a piercing of the penis that is usually, though not always, a metal ring.
When used in cases of erectile dysfunction they are known by various names such as "erection ring" and "tension ring".
A man may wear an erection ring because he has erectile dysfunction (ED) or hyperfunction. When used for ED, a purpose-designed vacuum pump is used to produce an erection by simple mechanical and hydrodynamical action in spite of vascular or nerve damage, and the ring slid off the pump's cylinder onto the base of the penis to maintain the erection before it is lost. The testicles are not ringed in this case.
A cock ring may be used to prolong erection because the wearer likes the particular sensation of tightness and extreme engorgement that wearing one provides. It can be worn as a sex toy, as genital jewelry, or simply for the appearance. Some men enjoy using cock rings for masturbation, as wearing of this sex toy contributes to better erection and delays orgasm, thus it intensifies orgasmic sensations. Also vibrating cock rings deliver a great range of very pleasurable vibrations that enhance enjoyment.
The purpose of a cock ring is to trap blood inside the penis in order to maintain an erection, or encourage a stronger erection. In order to do this it must be placed at the base of the penis.
A ring made of stretchy material is simply stretched over the penis (and optionally also the scrotum, except when used with a pump for impotence) and situated against the body. Rigid rings are used differently: first each testicle is fed through the ring and the entire scrotum is pulled through, then the flaccid penis is pushed through the ring and situated against the body.
When used with a pump a lubricating gel is always used to help the pump to maintain a vacuum (in the same way as vacuum grease is used with a vacuum pump in scientific applications). The gel also helps to slide the ring off the pump, and later to remove it from the penis.
Some models include a protruding clitoral stimulator, designed to tickle the clitoris, vulva, or anus during sex (and during masturbation on using them on a dildo). Others, such as the vibrating ring, vibrate, either vibrating the ring itself, or in a popular 'Dolphin' variant using two removable bullet vibrators to provide stimulation to the testicles and clitoris. Some cock rings have vibrators attached that can be worn to stimulate the scrotum or perineum of a partner during sexual intercourse. Many women find that rings with vibrator attachments provide clitoral stimulation that is needed for achieving orgasm. Cock ring users should keep in mind that any pain, discomfort, or feeling of coldness in genitals is a signal to take the cock ring off.
Another variation is an inflatable cock ring for added control of adjustment.
A triple cock ring or triple crown is a cock ring that has additional rings for restraining the testicles. In orgasm, the testicles usually retract towards the body before ejaculation. A triple crown changes and intensifies the sensation of orgasm by forcing the testicles to stay away from the body.
Vendors of cock rings and medical sources always indicate that cock rings are not to be worn for more than about 30 minutes. Falling asleep or using illicit drugs at the same time is very dangerous. The first sign of pending problems are when the penis starts to become numb or pallid. As soon as this happens, the cock ring must be removed.
To ensure that cock rings easily come off, the latest ones have quick release mechanisms to avoid having to struggle with pulling the rubber ring from the base of the penis. Cock rings should not be used without medical advice by individuals who are on blood thinning medications, those who have heart disease or sickle-cell disease. Diabetes is very often accompanied by ED, and pumps and rings are often recommended or prescribed medically.
Cock rings may slip off. Removing an elastic ring can be difficult as it may become entangled, inconveniently and painfully, in pubic hair. Some can cause severe tightening of the scrotum. Cock rings are best used with some type of personal lubricant. Where a ring is frequently used, as for ED, it may be desirable to trim or remove the pubic hair.
Medical issues 
Cock rings that are too tight, or worn for too long can be dangerous: this may cause priapism, a medical emergency that, if not treated promptly, can result in severe and permanent damage, including penile gangrene that can result in the destruction and possible amputation of the penis. Rings for erectile dysfunction are invariably supplied with the instruction that they should not be left on for more than thirty minutes. Falling asleep with a ring on is a particular danger. This may lead to temporary or permanent nerve damage. Numbness in the glans penis, penis becoming cold or penis becoming white may be signs that a cock ring has been worn for too long and medical advice should be sought.
Elastic, stretchy rings are removed by stretching them and pulling them off the penis, over the head, which can be difficult. Some have handles which can be grasped and pulled to stretch the ring much more easily than a simple ring can be expanded. Others have a quick-release mechanism allowing them to be easily removed without the need to do this. Some (not for erectile dysfunction) are designed to allow limited blood return, such as by hard beads that cause the ring to roll back and forth during use, increasing circulation.
When used for extreme or total erectile dysfunction, it must be possible to fit the ring onto the erect penis immediately after an erection has been produced by the pump; this practically mandates the use of very flexible rings that can be fitted on the outside of the pump's cylinder, and slid onto the penis without removing it from the cylinder when erection has been maintained.
Cock rings must not be used without medical advice by those who have cardiovascular problems or who take blood-thinning medication.
Materials and types 
Cock rings are made from many materials including leather, rubber, silicone, nylon, metal and even plastic. Many of the newer rings also have different accessories and projections. There are also vibrating cock rings available which can stimulate the testes at the same time.
Today, cock rings can be bought with accessories that stimulate the clitoris or anal area during intercourse. Other cocks rings go around the scrotum and can significantly enhance erection and intensity of orgasms.
However, there is one negative; the more accessories that are added on, the greater the chance of developing discomfort or cold sensations from the device.
Rings for ED must be able to be placed in position while a pump is connected; the erection is lost as soon as vacuum is removed unless the ring is already in place. This rules out most types other than simple elastic rings.
Specialized underwear 
Specialized underwear is available which comes with pre-fitted cock rings. The underwear has a pouch with an internal fabric/elastic cock ring, or "C-ring", which either slides along the penis and encircles the scrotum or, alternatively, simply snaps around the base of the scrotum to snugly—but not in a constricting way—attach the pouch to the genitals. As one walks, the C ring enhances the erogenous zone.
See also 
- Freddy and Eddy: How Use a Cock Ring
- Considering cock rings Retrieved on 2010-03-03
- Penis rings: What to do Retrieved on 2010-03-03
- Questions and answers on cock rings Retrieved on 2010-03-03
- How to put on a cock ring Retrieved on 2010-03-03
Media related to cock rings at Wikimedia Commons