Combining the iconic design of the original D-Series regulators with the latest advances in breathing performance technology, SCUBAPRO engineers have created a 21st century regulator in terms of quality, reliability, performance and style. The D420 features balanced valve inside a housing supported by a full metal structure. Called the Progressive Flow Control Valve, it is able to deliver abundant airflow for the best breathing performance, with a natural smoothness comparable to what you might experience breathing on the surface. The uniquely shaped fiberglass-reinforced nylon casing is ultra-durable and allows the LP hose to be connected on either the right or left side for maximum rigging flexibility. A dive/pre-dive system includes a switch on the top of the casing with a thumb tab for adjusting the direction of airflow right out of the valve. The highly efficient purge button is a technical jewel based on a new concept that gives the D420 its unique face. Teamed with the venerable MK25 EVO balanced piston first stage, this is a regulator system purpose-designed for today’s avid divers and SCUBAPRO brand enthusiasts everywhere.