The Swiss made APAG Goldach Air Master is my rarest regulator. I only know of two other collections that have one. The others are purple and yellow. This is the only green one I have ever seen. I do not know what, if any significance the colour has. One odd detail to note about this DIN vintage scuba regulator is that the nozzle does not have groove for an o ring as do other DIN regulators. I do not know for sure, but I suspect that the regulator was sealed using a hard disk like gasket that was placed in the valve of the tank. From the one advert that I have seen of this regulator is appeared to come with no hose clamps. It has been speculated that the hoses were held in place by a glue, but this is not known for sure. This model came to me with the original hoses, but not the mouthpiece. I have dressed it in US Divers hoses and mouthpiece for display. I hope to some day restore it properly.
UPDATE! I have located the correct mouthpiece for this very rare Swiss regulator and it is now restored to it's former glory.
The case appears to be made of Aluminum. Any information that you may have about this regulator would be welcomed and appreciated.