Used Scubapro MK 25 Evo / S620TI Dive Regulator System

The MK25 EVO is a balanced piston first stage — it delivers the highest airflow and instant response, and it is the choice of many performance-focused and warm-to-cold water divers. The MK17 EVO2 is a sealed diaphragm first stage — its internals are isolated from water, which makes it the traditional pick for very cold water and silty or salty conditions with less maintenance sensitivity. Both are excellent; choose the MK25 EVO for maximum performance and adjustability, the MK17 EVO2 for a fully sealed set-and-forget workhorse.

Yoke (INT) is the most common fitting on rental tanks in North America and the Caribbean, so it is the simplest choice if you mostly dive at resorts. DIN screws directly into the tank valve, is rated for higher pressures, and is standard in Europe and technical diving — and a DIN regulator can use a simple adapter on yoke tanks, which makes DIN the more flexible long-term choice for traveling divers. ScubaPro sells both versions, and a yoke regulator can later be converted to DIN by an authorized dealer using a genuine ScubaPro conversion kit (DIN owners going the other way simply use a DIN-to-yoke adapter — no conversion needed).

The EVO generation added ScubaPro's XTIS (Extended Thermal Insulating System), which improves freezing resistance in cold water, along with updated materials and finishes. The core balanced-piston design that made the MK25 famous is unchanged — the EVO is the same performance with better cold-water protection.

Ti refers to the S620Ti's titanium components — the inlet tube and barrel are full titanium, making the second stage ultralight and highly corrosion-resistant, housed in a rugged fiber-reinforced technopolymer casing. It is the successor to ScubaPro's legendary S600: smaller and lighter, but with the same-size diaphragm for effortless airflow in all conditions. Paired with the MK25 EVO first stage, the system is cold-water rated.

ScubaPro's official recommendation is a full service by an authorized ScubaPro technician every 2 years or 100 dives, whichever comes first. If you dive heavily (100+ dives a year), ScubaPro recommends an inspection every 6 months and an overhaul annually. Staying on schedule also keeps you eligible for ScubaPro's Parts For Life program — free service parts for the original owner when the regulator is registered and purchased as part of a qualifying package from an authorized dealer. As an authorized ScubaPro dealer, we can help with registration and service when it is due.

Follow the interval in your regulator's manual, since manufacturers commonly specify an annual inspection or a set number of dives and many warranties depend on it. A regulator is life-support equipment, so service belongs with a factory-trained technician rather than being attempted at home. Have it looked at sooner than scheduled if you notice increased breathing effort, free-flow, bubbles, or water in the second stage.

Make sure the dust cap is dry and firmly seated over the first-stage inlet before the regulator goes anywhere near water, because water inside the first stage is the leading cause of internal corrosion. Rinse in fresh water without pressing the purge button, since purging while depressurized can draw water back into the second stage. Shake out the water and hang it to dry with the hoses in wide, gentle loops rather than tight bends.

Regulators travel well and are usually best carried in hand luggage where they will not be crushed or lost. A regulator holds no gas of its own, so there is nothing inherently problematic about it on an aircraft, though the airline and security screeners always have the final say. Pack it dry with the dust cap in place, in a padded regulator bag or wrapped in soft gear.

Many modern regulators are supplied as suitable for nitrox mixes up to 40 percent oxygen, which is the widely used recreational industry standard, while anything above that requires dedicated oxygen-clean equipment and procedures. Confirm what your specific regulator's manual states, and follow your nitrox training and your fill station's requirements. Never assume a regulator is oxygen-service clean simply because it looks clean or is new.

A yoke (A-clamp) fitting clamps over the tank valve and is the most common connection across much of the recreational world, while a DIN fitting screws into the valve and is standard in much of Europe and in technical diving. DIN captures the o-ring inside the threads, which many divers consider more secure, but yoke is often what rental cylinders provide. Adapters exist in both directions, so check what is used where you dive before deciding.

The octopus is your backup second stage, carried so you can share air with a buddy who is out of gas, or breathe from it yourself if your primary fails or free-flows. It is normally on a longer, brightly colored hose so it is easy to find and hand over under stress. Secure it in the triangle between your chin and the bottom of your rib cage so it is instantly accessible and not dragging through sand or coral.

Store it fully dry, out of sunlight, with the dust cap in place and the hoses in wide loops rather than tightly coiled. Avoid hanging it by the second stages for long periods, which stresses the hose fittings; laying it flat in a padded bag or hanging it by the first stage is kinder. If it has sat unused for a long stretch, have it checked before your next trip rather than assuming it is ready to dive.