I bought this beauty a few months ago here on this site from the original owner . I love the look of this device it's just a little too big for me. Cage comes with one key and one screw. Added security of having screw countersunk so that wearer is unable to use pliers to loosen the screw. Cage is 2 1/2", base ring is 2 1/8" OVAL, gap is 1/4", interior dimension is 1 3/8”. Cost new would be $425 with a 6-week lead time, this one can be in your hands next week for $300 + shipping. It's a beautiful device!