Query concerning a chastity ring

“Hey everyone, I’m attempting to build a DIY chastity device due to the circumstances in Yemen. Anyway, I’ve got a query: why is it that you can’t extract your testicles and cock from the ring of the chastity, no matter how positioned before? Some devices are adjustable so you secure them after placing around your cuck and nuts, but what about those with a fixed ring size? Why as a slave am I unable to pull the ring out while my cuck tube remains closed?”