I ordered the sizing rings from MM in January and spent a couple of weeks measuring. If you are thinking about ordering from MM start with the sizing rings. Decided on WM cage with 1/4" gap. Diameter of cage is 1 1/8". Ordered 2 base rings. First was an oval single ring at 1 5/8". Second was round double ring at 1 11/16". Started in mid April wearing double round ring. It was amazing. After wearing CB6000s for around 9 months I knew day 1 in my WM that I could sell my plastic friend. After 3 months with the 1 11/16" double ring I noticed that things were getting more loose. In the morning I would find my WM slid down. Decided to try 1 5/8" single oval. The fit was much more snug. Nightime sliding ended but scrotum burn started. Then I remembered a post discussing making a single ring into double to address scrotum burn. Two weeks with the 1 5/8 " double oval ring and what a world of difference. No burn at all. Yard work, bike riding, painting all no problem. Up to 4 ruined orgasms thanks to my KH.