Is the 1 inch the inner diameter or the outer diameter? Are any key rings that are sold in a national recognized store that are labeled as 1" acceptable? A 1" key ring is more then 1" because of the thickness of the metal.

The measurement listed in the rules is approximately 1/2 to 1 inch to allow for measurements taken on the inner or outer diameter of the key ring. Yes, a key ring that is labeled as 1" is acceptable.