This single hose, two-stage, demand regulator was manufactured and marketed by E.R. Cross from 1948 to 1953. During this period Cross owned and operated the Sparking School of Deep Sea Diving in Wilmington, California, and sold this unit, compete with an air cylinder and webbing harness through his Divers Supply company for US$79.95. It was available at roughly the same time the first Aqua Lung systems arrived in America.
This regulator is currently the only surviving one recording by the Historical Diving Society. It was acquired from Mr. Cross personally by Leslie Leaney, and is now part of the ISDHF Collection. E.R. Cross is an inductee in the International Scuba Diving Hall of Fame.