R.E.L. means Research Enterprises Limited and was founded by the Canadian Government on July 1940. From 5 june 1941 optical glass came into production in Toronto. Rangefinders, Tankperiscopes, radar equipement and binoculars were produced.
50.000 6 x 30 binoculars and 25.000 7 x 50 binoculars were produced. They were tested by dropping them 1.80 meter into a box filled with sand. They were also sprayed with water.
C.G.B. means "Contract Great Britain" GA means "with case"
This example has no reticle, others do. The two screws centre of the prism plate are used for nitrogen purging. This pair came with the adaptor as well.