Help finding the right cage

[First-timer]

Hey everyone! I brought the idea of short term chastity up to my wife and she was super excited so we ordered one from Amazon right away, I measured my length but figured the rest would be fine. After trying the cheap Amazon one and feeling some discomfort and trying to adjust the ring gap I figured I should measure my ring size and got 70mm. I am having trouble finding one this size anywhere. I’ve measured multiple times but it just doesn’t seem right. I want to order a cage on the cheaper end since we are just getting started. I would like to one day be locked long term but my wife is still coming around to the idea. Any help is appreciated.