I started using them when I was having trouble mantaining an erection while putting a condom on. I think the basic lasso type is the best way to go. Don't keep it on for more twenty minutes at a time and you wont have any vascular problem.
Cock rings are effective in making an erection harder and reducing premature ejaculation..surprisin gly. But if your having ED issues then its not the antidote. The culprit could be be weak cock muscles. If your getting sex on the regular its not an issue but if you go weeks without then your cock has a tendancy to become weak. Your cock is fifty percent muscle so it just like not jogging for weeks if your a jogger. Your not going to be at your best.
Checkout a book on cock exercising and penis extenders do work. The traction devices. I have used for nine months and have added a inch and it has made me much stronger. It keeps your cock fit in the event your not getting sex on the regular.