All of Brownie's yellow hoses are compatible for both Hookah and Scuba pressure. This 12″ hose with 1st stage fitting to male QRS allows you to connect from a standard 1st stage / 1st stage fitting to any Brownie's Hookah yellow hose. A High Pressure 2nd stage regulator is required to complete this scuba tank configuration. Brownie's Hookah 2nd stage regulators are NOT compatible.