Ways to Size the Contender's Base Ring

Hi everyone, Before I post here, I did my best to search the sub-forum for info, but all my keywords (such as base ring and sizing ring) were rejected because they’re too common:o . So please forgive me if I’m asking a question that’s already been answered (which it almost certainly has). I’m looking to upgrade from an MCN Holy Trainer v2 Small with a 45mm ring diameter over to the MCN Contender. My rule for sizing is: pick the smallest diameter that feels comfortable when worn continuously for 24 or 48 hours. Here are some methods I know: Chastity sizing rings. Other shops sell these (not necessarily from MCN), but I’d like to keep them as a last resort. Comparing it with my HTv2. This isn’t really possible since the two cages differ completely in design. The thread method. When I got the HTv2, I measured myself using this straightforward technique (wrapping an inelastic thread or shoelace around my scrotum until snug and then measuring its length). It worked okay, but I feel it might not be ideal for a custom metal device. Plumbing metal/plastic rings. Mark from MCN suggested checking DIY stores for these, which I did without success (I’m neither in the US nor Europe, and DIY isn’t as prominent where I live). The Jubilee Clip. This is about as close to a sizing ring as I found at my local store. It’s obviously thinner and wider than an MCN ring; it would likely represent a CB6000 ring better, but could still work: I’m thinking of ordering the MCN base ring one size smaller than what the clip measures, accounting for its extra width (it’s about ~6mm wide). What do you think about using the jubilee clip method? Any other tips from the chastity masters here?:D