What do you know about cockrings?

Here some examples what is doing a cockring:

• Prolong male erection by holding blood inside the penis. A man may wear a cock-ring to combat erectile difficulties, or for the sensation of tightness and engorgement that wearing one provides. Some models include a protruding clitoral stimulator, designed to stimulate the clitoris during sex. Others vibrate, either vibrating the ring itself, or in a popular ‘Dolphin’ variant by using two removable bullet vibrators to provide stimulation to both the testicles and clitoris. Some cock rings also have vibrators attached which can be worn to stimulate a partner during sexual intercourse, especially in the scrotum or perineum. Yet other cock rings have arms that rub and apply pressure to the perineum of the wearer.
  • A triple crown is a special cock ring that has additional rings for restraining the testicles. In orgasm, the testicles usually retract toward the body before ejaculation. A triple crown changes and intensifies the sensation of orgasm by forcing the testicles to stay away from the body.
• A docking sleeve is a cylindrical device similar to a penis sleeve, but is open at both ends, so that two men can dock, a form of mutual masturbation.
• An FTM stroker is a pocket-pussy-style toy designed “for [the] t-cock/enlarged clitoris” of a transgender man on hormone replacement therapy. In 2016, Buck Angel released the first such device, the Buck-Off.
• A penis extension is a partially hollow device like a very short dildo, with the hollow end placed on the end of the penis, intended to increase the effective length of the penis, again for the benefit of the person being penetrated. These are generally worn with condoms to prevent them from falling off during use.
• A penis sleeve is a cylindrical device that is placed on the shaft of the penis, with the aim of increasing stimulation for the person being penetrated. They often have soft bumps intended to provide further stimulation.