Well my guy prefers the one that goes around both the balls and the base of the cock. Here is a quick definition of what they both do separately:
The purpose of a cock ring around the base is to trap blood inside the penis in order to maintain an erection, or encourage a stronger erection.
A double or triple cock ring is a cock ring that has additional rings for restraining the testicles (either together or separately). In orgasm, the testicles usually retract towards the body before ejaculation. These cock rings change and intensifies the sensation of orgasm by forcing the testicles to stay away from the body.
Double Cock Ring:
Tripple Cock Ring:
So, I’d recommend buying a standard cock ring (you can pick them up super cheap in rubber) and a either a double or tripple cock ring and give them both a try and see which you prefer :) xoxoxo