Can anyone advise me what the make/type/manufacturer is for the the generally available "Air-Arms" type male and female quick disconnect couplers is? These are the ones you often see on quick-fill modified cylinders. I am not talking about the smaller 'Foster' type that are found on the Daystate guns and are sold by Best Fittings. I have used these a lot and I am finding that the male couplers wear out, and then cause the female coupler to fail (emptying your cylinder!). They may be quick-release but should also perhaps be labelled "not for prolonged usage".