It really gripes me when a manufacturer will not state what size orings are in their gun. BSA comes to mind. Same for ball bearings. What's the deal? Are they making their bottom line on a few bucks for a .10 oring?
I applaud companies like Airmaks that make it easy, with a seperate diagram with all the orings needed.
In the US the oring store and orings and more are good and don't require a rediculous amount of minimum buy. When I buy an airgun, I go through whatever hoops are needed to find the sizes, and if need be buy a kit, then measure and order from one of those above. I keep plenty on hand so I don't have to wait if I have a breakdown.
I like Captn Orings for kits, but $30 for 15 or so orings for a Cricket is kind of getting clipped pretty good, when for $30 I could get enough for two lifetimes.
Before I trimmed the herd of guns down, I ordered in a quantity that helped offset shipping, but now, I only have four pcp's and probably enough orings for them to shoot a long long time.