Mature Metal Jailbird Included with this device are 2 keys and 3 security screws. Extra keys and screws are really nice because if you loose a key or security screw Mature Metal wont replace them ! I will also include a regular lock and key so you can compare the lock to the security screw. But, for long term wear , the security screw is clearly the way to go. Oval Ring 1 7/8" Gap 3/8" Cage Length 2 1/4" Cage inside diameter 1/1/4" Security screw option 1 7/8 inch and 3/8 inch gap is a very common ring size. I believe the cage will also be a common fit. Remember for cage sizing it is much preferable to be snug rather than loose. The device has been sterilized and is ready to ship. $215 OBO, US sales only, Payment is via PayPal, I will cover any pay pal fees, and will include USPS 3 day priority shipping.