How to determine Ring Size
All tension rings that fit around a cylinder are interchangeable with any erection device. The inside diameter of the ring doesn't matter, since they all have to stretch onto a cylinder that is between 2 to 2.5 inch in diameter. The material and flexibility of the ring determines the inside diameter and strength of the ring.
Trying to determine the size of your penis versus the size of the ring is pointless. Tension needed is based on blood flow, therefore everyone's level of tension is different in order to hold the erection. If you are larger in diameter start with the larger rings and work your way down until you find which holds the best for you. There are several types of rings ranging from tension to comfort and durability. Please contact us at 866-496-7359 if you need more assistance. Any website telling you to measure yourself and calculate the circumference has no clue of how to use this product and are just trying to convince you to buy something.