In this package you get a solid second step that can be adapted to exactly what you prefer and a first step made with an eye for simplicity and easy breathing, at a reasonable price.
Apeks' DS4 first stage is sealed against water, and adapts to your depth using a membrane that transfers the pressure to the membrane that controls the air pressure. This first stage uses an overbalanced diaphragm design that provides greater flow at deeper depths than traditional balanced models. The result is good and easy breathing, no matter how deep you dive.
The DS4 first stage has 4 medium pressure outlets in size 3/8 UNF and 1 high pressure outlet in size 7/16 UNF
The Apeks XTX 40 is another step up, built on the respected XTX series, and adds features such as integrated venturi control and the ability to convert to right/left orientation.
Apeks XTX 40 purge button in a separate piece of plastic from the rest of the front, to provide better protection of the inside of the regulator during use. The XTX 40 can be equipped with a swivel joint in the hose connector to give freedom of positioning during the dive.
The XTX 40 comes standard with short air outlets, but can be converted with longer outlets to provide fewer bubbles around your face and better options for e.g. to take pictures. The XTX 40's short air outlets provide a compact and easy-to-handle regulator, perfect for use as an octopus or as a lightweight regulator for comfortable diving.