baccart;
Cock rings probably won’t do much to retard ejaculation. What they are good for is keeping an erection hard and this might be of some benefit to you in sustaining the erection for awhile after you cum.
They shouldn’t be worn for longer than 30 minutes at a time (we’re talking about the type that fits over the shaft only here) because of circulation concerns. I can’t think of any other negatives about their use.
What can help in premature ejaculation is Kegel exercises over time. And there are several members who have said that PE exercisess in general have helped them a whole lot in being able to last longer during sex.