What Scubapro has to say (the technical bits):

The MK19 EVO/G260 is a rugged, reliable, and sharp-looking regulator system that delivers solid breathing performance in all diving conditions and water temperatures.

FIRST STAGE: Designed to be the ultimate first stage for cold water or contaminated diving conditions. 

Its design makes it substantially smaller and lighter than the original MK19. 

Air-balanced diaphragm delivers consistent and effortless airflow, regardless of depth, tank pressure, or breathing rate. 

Environmentally sealed system prevents water and pollutants from fouling the inner mechanism. 

Its dry chamber is equipped with a double spring, making it more compact and reliable. 

Two opposing high-pressure ports allow the first stage to be positioned either up or down, plus provide for an optimum hose/transmitter layout. 

Swivel turret comes with four High-Flow LP ports plus one axial Super High-Flow LP port to maximise hose routing options. 

Compact size, light weight and superb breathing performance continue in the best SCUBAPRO regulator tradition. 

Ideal first stage for recreational, technical, professional and military divers. 

Weight: INT 232, 885g; DIN 300, 665g 

Airflow at 2900psi/200bar: (l/min/SCFM): >6,900/244 

Intermediate pressure (psi/bar): 133-142/9.2-9.8

SECOND STAGE: Air-balanced valve smoothes out the inhalation effort at varying depths and supply pressures 

Nylon fiberglass design features SCUBAPRO’s biggest second stage casing and diaphragm for the ultimate in breathing sensitivity, regardless of position in the water 

Metal components, including metal air barrel and metal valve inlet tube, increase resistance to freezing when diving in extreme conditions 

High-flow exhaust valve reduces exhalation for better overall breathing comfort 

A diver-adjustable inhalation effort knob fine-tunes air delivery to suit changing depths water conditions and personal tastes 

Venturi-Initiated Vacuum Assist (VIVA) dive/pre-dive switch prevents free flows in cold water or when used as an octopus 

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 

Ultra-comfortable orthodontic mouthpiece is easy to grip yet doesn’t inhibit airflow 

Airflow at 200bar: 1800 l/min