The construction of the first stage gives it excellent resistance to corrosion, durability, as well as faster dynamic response and extra high flow.
The second stage was developed to improve regulator performance in every area. For extra demanding divers that want the top of the line regulator.

Machined marine grade chrome plated brass body
Thermal Insulating System (TIS) on piston and spring
Straight coaxial flow valve
Dive/pre-dive control switch To prevent accidental free flow.
Manufacturers Website.