Guidance needed on picking the proper cage

Hi all! I mentioned short-term chastity to my wife, and she was really enthusiastic. We grabbed one from Amazon immediately. While I took care of measuring the length, I assumed the rest would work out fine. However, after using that budget-friendly Amazon model, I experienced some discomfort while trying to tweak the ring gap. This made me realize I needed to measure my actual ring size, which came back at 70mm. Now, it’s proving difficult to locate a cage in this specific dimension anywhere online. I’ve double-checked and triple-checked the measurement, but something still feels off. Since we’re early days, I’d prefer to keep costs down when ordering a new one. My long-term goal is eventually being locked indefinitely, though my wife is currently warming up to that concept.