This is by far the best regulator I have ever used and my personal favorite. It breathes effortlessly at any depth and in any conditions as well as any orientation with ZERO water fill in the mouthpiece. It is the only regulator I have used that I was able to dive upsidedown for extended periods and not got any water buildup in the reg.

First Stage:

• Air balanced flow-through piston provides constant and effortless airflow unaffected by depth, tank pressure, or breathing rate.
• Patented XTIS (Extended thermal Insulating system) thermally insulates the inner mechanism from the environment, improving cold-water resistance and delaying ice formation in extreme cold-water conditions
• Anti-freeze protection radically increases breathing reliability when diving in the most extreme water temperatures.
• Two opposing high pressure ports allow the first stage to be positioned either up or down.
• Four high-flow and one axial super high-flow low pressure ports on a swivel turret maximize hose routing options.
• External intermediate pressure adjustment enables technicians to fine-tune performance quickly and easily.

Second Stage:

• Air balanced second stage valve smoothes out the inhalation effort at varying depths and supply pressures.
• Rugged reinforced technopolymer design features SCUBAPRO's largest second stage casing and diaphragm for the ultimate in breathing sensitivity, regardless of position in the water.
• Metal components (inlet tube, orifice, inhalation control knob and hose connector) increase resistance to freezing when diving in extreme conditions.
• A diver-adjustable inhalation effort knob fine-tunes air delivery to suit changing depths, water conditions and personal tastes, and a Venturi-Initiated Vacuum Assist (VIVA) dive/pre-dive switch prevents free flows in cold water or when used as an octopus.
• High-flow exhaust valve reduces exhalation for better overall breathing comfort, and the reversible hose attachment allows you to easily adjust hose routing for tech diving configurations.
• Super-flow hose features an oversized bore that allows more air to flow on each inhalation.

Same as SCUBAPRO S360 Second Stage, except with yellow face cover. Based on the new 560 Second Stage, but with Pre-Tuned Inhalation for Uncomplicated-Use. It's an ideal choice for avid divers wanting Performance yet a simple to Operate-System. The S360 Otcopus is an Air-Balanced-Flow-Valve Design with a Techno-Polymer Barrel with a Rugged, Precision Molded Carbon Fiber and Techno-Polymer Case. The Diver Adjustable Venturi Initiated Vacuum Assist (VIVA) Dive/Pre-Dive Control Switch and Extra High Flow Exhaust Valve account for Easy Inhalation & Exhalation at any Depth or Breathing Rate.

• Pre-Tuned Inhalation for Uncomplicated-Use
• Air-Balanced-Flow-Valve Design
• Techno-Polymer Valve Barrel
• Rugged, Precision Molded Carbon Fiber and Techno-Polymer Case
• VIVA: Dive/Pre-Dive Control Switch