The Mares V42 Proton Metal regulator. The most compact regulator characterized by its "all metal" technology. The smallest and lightest diaphragm first stage available. The V42 first stage guarantees exceptional performance and optimum placement of the hoses, too. The small metal second stage offers great performance and offers an oversized purge button.

The presence of the metal in the body of the second stage noticeably decreases abrupt changes in temperature. In fact, metal is a good conductor of temperature, and makes the water surrounding the second stage act as a heating element for the air inside. Strange as it may seem, the water, even at a temperature of just a few degrees above freezing, may be considered "warm" in comparison with the air expanding inside the second stage.