Scubapro MK20/D400

About this certified used regulators

High-performance regulator pairing featuring the legendary Scubapro MK20 balanced piston first stage and the uniquely engineered D400 second stage. Widely considered a milestone in scuba engineering, this vintage setup is highly sought after by collectors, tech divers, and retro gear enthusiasts for its exceptionally smooth, low-effort breathing characteristics.The MK20 First Stage is a bulletproof, balanced linear flow-through piston design that ensures consistent air delivery regardless of tank pressure or depth. It features a convenient swivel turret for clean, streamlined hose routing.The D400 Second Stage is a masterpiece of classic Scubapro design. Utilizing a unique coaxial flow valve and an aerodynamic, fiberglass-reinforced nylon body, it positions the exhaust valve at the bottom of the casing. This design directs air horizontally to minimize the physical effort required to breathe (Work of Breathing) while keeping exhaust bubbles completely out of your field of view. Specifications & Details First Stage: Scubapro MK20 (Balanced Flow-Through Piston)Second Stage: Scubapro D400 (Coaxial Flow / Axis Valve Design) Hose Routing: Swivel turret with multiple low-pressure (LP) and high-pressure (HP) ports Controls: External dive/pre-dive tuning knob on the D400 to prevent free-flows at the surface Condition: Pre-owned with typical cosmetic surface scuffs from normal dive use. Body, casings, and fittings are structurally sound.

Like every piece of used dive gear on DescendAgain, this one went through a certified technician's bench before it was listed: stripped, serviced with the right parts, tested beyond manufacturer specification, honestly graded for cosmetics, and covered by our Certified Pre-Owned warranty. It ships from the dealer that serviced it.

Before you buy Read the technician’s guide: How to Inspect a Used Regulator: A Bench Technician’s Checklist