Solid brass construction for maximum durability. Oxygen Compatible Materials and O- Rings. Inlet adapters can be removed to expose 3/8"-24 female ports. Allowing for flexibility of hose attachments. Quick Disconnects attach directly to the inlet port alleviating the need for more adapters. The OmniSwivel Gas Switch Block allows a diver to change between two separate air tanks without having to remove their full face mask. The knob turns a full 180 degrees ensuring that there is no accidental switching during the dive. The knob pointing to the first position(as shown in top photo) signifies that the air source closest to the outlet is in use. The center photo shows the GSB in the shut-off position. In case of a second stage failure, a diver can turn the flow off to mask and switch to an alternative regulator. This shut-off position also prevents a cross blending of gases during a switch over.