The green label Sea Lion ATLANTIC demand regulator out of the United Kingdom boasted a nylon return valve mouthpiece, venturi action, spiral breathing hoses that stretched to twice original length,as well as a pressure take off for a contents gauge (submersible pressure gauge).  This regulator sold for about 17 pounds.  Submarine Products was one of three companies to make double hose SCUBA in the UK. Siebe Gorman and Heinke were the other two. By 1960  Siebe Gorman owned all of them. Submarine Products made the Sea Lion, Sea Lion II, Super Sea Lion, Atlantic, and the Black Prince. The Black Prince was also relabeled and sold by Cavalero in France.