Sorry - we don't check every day, but try to at least once or twice a week. The answer is - according to Aqua Lung all of the regulators they are now selling have the larger orifice except the Conshelf, so the Kronos should be our size II. However, we did get one report from a customer that our size III fit a Kronos perfectly. The III is the same diameter as a I, so that doesn't make sense. So, it should be a II, but it would be safest to buy it from a dive store where you can try it on before you buy it.