In this case the intermediate pressure is most commonly supplied in the 80 to 110 psi range For the lower range a Hookah Conversion kit is available A robust, over-built design for the heavy commercial style use Venturi deflector to prevent accidental free flows Simple and easy to service For divers, hookah refers to the breathing gas being supplied from the surface Commonly done by leaving the cylinder on the surface and a long low pressure hose between the first and second stages