The company APAG – Apparatebau A.G. – Goldach started its activities in 1955 in the city of Goldach, Switzerland. It was sewing machine manufacturer. During the 60s and 70s, produced diving equipment.
The company produced initially 125 bar cylinders and subsequently the Air Master double hose regulators.
Air Master regulators have been produced in various colors. It is a unbalanced double hose regulator and upstream single stage. There are versions of 5 and 6 screws sets.
The mouthpieces produced by APAG for the AIR MASTER were also used in double hose regulators Schick S.C.U.B.A and Airomat from Mohnsam.
Reference
1. http://www.tauchclubwinterthur.ch/index.php?option=com_content&task=view&id=51&Itemid=49
2. Frank Werthwein