Air-balanced valve technology. The air-balanced valve technology of SCUBAPRO’s second stages features a balancing chamber in the second stage mechanism, slightly offsetting the force of the downstream air entering from the first stage. This allows reduced spring tension and decreases the inhalation resistance to the lowest possible level. The result is super smooth breathing in all conditions. The air-balanced valve technology is featured in the X and S-Series second stages. For best results they should be combined with balanced first stages, like the MK25 or MK17.

Diver adjustable inhalation effort. This feature enables the diver to adjust breathing effort via an oversized control knob; it is available on the X650, S600, and G250 second stages. All other second stages feature a pre-set inhalation effort that suits the most common diving conditions and can be fine tuned at an Authorized SCUBAPRO Dealer on request.

Venturi Initiated Vacuum Assist (VIVA). Another SCUBAPRO patented feature, the VIVA is available on all SCUBAPRO second stages. VIVA uses the power of a vacuum assist to reduce work of breathing and increase breathing comfort. It is diver adjustable on all current SCUBAPRO second stages except the R295, since it is a second stage intentionally designed for diver training courses, rental facilities, and divers demanding ready to use equipment. A VIVA in MAX position gives powerful breathing support on every single breath; a VIVA in MIN position helps to prevent free flow on the surface, for training, for buddy breathing, in currents, or when used as an octopus.

Orthodontic mouthpiece. SCUBAPRO uses a comfortable orthodontic mouthpiece on every second stage to reduce jaw fatigue and gum irritation. It was developed by dentists and dental laboratories and lasts longer than any other mouthpiece, because only a minimum effort is needed to hold it comfortably in place.