Just wondering, cause I got a friend that put it around his penis all the time but no longer than 30 minutes and its not tight. Now we're getting somewhere. A cock ring traps blood in the penis. Since blood is what makes an erection hard, more blood makes an erection even harder. Men experience increased sensitivity along with bigger, harder erections. A cock ring also holds your penis and testicles slightly away from the body, which makes them look bigger, too.