Chastity device discussions and reviews discussion

Hi everyone. We purchased a metal contraption as our initial one. It works well for brief periods (taking it on and off throughout the day). Yesterday I was instructed to keep it on for a full day; I managed, though there were moments of sharp pain, and upon removal I noticed a red mark left by the base ring. I’ve spotted new rings popping up somewhere but haven’t been able to track them down yet. The one we own measures just 40mm I’ve included an image of the ring. Any assistance would be greatly appreciated.