Cock rings

I bought a multi pack of heavy-duty cock rings the other day and they duly arrived, but without any instructions.  How do you wear them?  In front or behind your balls?

depend if its a multi ring slip a bullock inside the biggest then the other bullock then tuck your cock through, make sure you use lube or your burst a blood vessel on your shaft. then feed the other rings over your cock. its a knack. hard to get on if you get a stuffy as soon as you touch yourself