Fine-tune your breathing dynamics with the Explorer Pro&';s adjustable external air intake mechanism. The integrated internal deflector ensures smooth respiration throughout your dive, while the featherweight 7 oz construction reduces strain on your jaw during extended underwater sessions. A generously sized exhaust valve facilitates efficient expulsion of breath for optimal comfort and control. External air intake resistance adjustment system. Internal air deflector for smooth and easy breathing. Lightweight and compact, weights merely 7 oz without the hose. Prevents jaw fatigue during long dives. Large diameter exhaust valve allows for proper removal of exhaled air. Recommended 1st stage: DF300, DF300E, RG100, RG050