The all chrome plated marine brass first stage regulator is a balanced diaphragm design which is environmentally sealed. The first stage has two high flow low pressure ports (LP) and two standard LP ports along with two high pressure ports (HP). The high flow LP ports are positioned near the diaphragm and offer up to a 15% increase in air flow. The RS-790 second stage is also a pneumatically balanced system. A small chamber positioned at the end of the poppet assembly traps air and forces the poppet back against the intermediate pressure orifice. This provides decreased inhalation resistance and increases smooth breathing in all conditions. The lightweight compact composite designed second stage is also equipped with a Venturi Adjustment Lever. This lever has two positions that are selectable by the diver. Use Surface" or minimum setting when entering the water or on the surface, reducing the sensitivity and possible free flow of the second stage. Use the Dive" or maximum setting for maximum air flow during the dive. The second stage comes standard with an orthodontic-conscious designed silicone mouthpiece. The RS-790 is nitrox compatible to 40%, comes with a comprehensive Owner's Manual and is covered by TUSA's limited lifetime warranty.