Scubapro R195 Ultra-comfortable orthodontic mouthpiece is easy to grip yet doesn't inhibit airflow. Rugged reinforced technopolymer casing is fitted with a large diaphragm for the ultimate in breathing sensitivity, regardless of position in the water. Classic downstream valve comes with a VIVA switch to control free flows. Metal valve housing is built rugged and increases overall reliability. Reversible hose attachment makes it easy to use on deco tanks.