We got a clear holy trainer last year with a standard ring, and it fit me too far away from my body, so we ordered a small ring. Unfortunately, it seems like the holy trainer is not good for my body type, as it doesn't stay close to my abdomen and hangs very low. Will consider offers to sell, includes two keys, standard and small ring, and the clear holy trainer.
It's the "standard" model: Length inside the tube : 60 mm Inside diameter of the tube : 35 mm Number of air holes : 0