Started my chastity experience with a CB-3000 but found quickly it was no good for me. It was so small that the tip of my penis always poked out the end and rubbed on anything I was wearing. i couldn't wear it for any length of time. I persevered but eventually gave up and bought a Curve.
I tested it a few times and it fitted great, though it's a bit bulky. After 3 days without orgasm by will power alone, I fitted it after coming home from work. It hardly shows when you're walking around, but sticks out a bit when sitting.
I had to go out with it on in the car to the shops - it wasn't long before I started getting horny. It's hot and sunny here and the girls look gorgeous....
I kept it on for about 6 hrs then took it off before going to pick my wife up from work.
I told her about it and it made her horny too. She told me to leave it off and we had the most amazing sex with a mind blowing orgasm for me.... Defeats the point of the chastity device I know, but these are early days.
She has told me that she wants me to get comfortable in it then she takes the key off me...
Back locked again today - a little sore behind the balls though (where the hinge of the ring is).