The RS-790 delivers performance, durability and comfort making it the ideal choice for discerning divers. The R-700 is a balanced diaphragm first stage designed for cold-water use, it features a dry ambient pressure chamber that prevents water contact with the diaphragm maximizing performance in temperate water conditions below 50°F/10°C. Additionally, the R-700 has an external rib section that nearly doubles the surface area for thermal exchange further reducing ice formation that can lead to freeze up in extreme conditions. The R-700 has two high pressure ports and four low pressure ports including two high flow (HF) that deliver up to a 15% increase in air flow. It is available in both INT (yoke) and DIN versions.