Extreme Product Feature – MK21 S560

I’m sure you noticed today isn’t Wednesday. If you didn’t… well I’m helping you out… Today is in fact, not Wednesday. Okay now that we have that cleared up, you’re looking for my excuse, right? Well let’s just say a family emergency came up and on the true Wednesday I was spent. All is well now, though so let’s proceed on and just learn about this week’s SCUBAPRO Feature item, the MK21/S560. That’s a regulator in case you weren’t real sure. So glad I could help there!

This duo combination received the 2014 Gear of the Year award in Scuba Diving Magazine and was the Editor’s Pick in Sport Diver Magazine, April 2015.

So this excellent mid-range regulator system is lightweight and compact, but a very versatile breathing system that offers superb performance and value plus a whole lot more.

The MK 21 is SCUBAPRO’s super compact, balanced-piston first stage regulator. It is smaller and lighter than the MK25, using a smaller piston but delivering the same performance level of breathing no matter the depth or breathing workload. The design allows for resistance to freezing due to the thermal exchange while being a stylish polished chrome brass body. Wait a minute… what is thermal exchange? Basically it is the regulating of the air in the equipment. That means, the cooler diving temperatures you reach, the regulator regulates the air temperature helping to keep from freezing, definitely a bonus if you’re diving and still want to breathe, lol .

One of the features of the MK21 is their innovative “smart” hose layout. Okay miss blogger lady, what is that? The standard cap that comes on the MK21 has 4 low pressure ports that are angled (+/– 20˚) to maximize hose routing. Then there is a fifth port designated as as the high pressure port. Are you confused yet? Please tell me this blogger lady isn’t the only one confused! So I’m going to lay this out as if you are as confused as I was.

In this picture you see those ports? (they’re labeled). The standard cap comes with 4 low pressure ports. Now pick your regulator up if you need to, don’t worry I have the MK21 that is in the picture sitting on my lap as I’m trying to describe this… Typically, the “normal” if that’s possible, regulator usually only has 2 low pressure hoses coming off of it. So there are ports that are not being used. Remember your 1st stage sits on the tank and reduces the air pressure from 3000psi down to 140psi. Those are your low pressure ports. The HP or High Pressure port usually has your computer information attached to it (whether it be your transmitter or your computer to tell you pressure left in your tank). With me so far? I sure hope I’m with me.

So the angled portion of the ports allows the hoses to, instead of coming off the port at a 90˚ angle, it comes off at an angle +/– 20˚ from that and allows the hose that much more room to get that regulator to your mouth. So basically it is like you gain just a little bit of hose. So by default it comes with the 4 low pressure port cap but that cap can be replaced by a certified SCUBAPRO dealer to give you 5 low pressure ports.

So why would you need so many ports if normally you have 2 hoses coming out of 4? One example I can give you would be my darling husband, Mark’s set up. Out of his low pressure ports he has the second stage regulator, the air two hose, a secondary hose for his alternate inflator on his BC, and a drysuit hose. Hopefully between the picture, the explanation, and the example it makes things clear as mud . Hey, I’m running 3 days on about 6-8 hours of sleep total when normally it would be more like 16ish hours of sleep.

Let’s move on to the air balanced S560. This second stage features a lightweight techno-polymer casing and comes with full user controls, including an inhalation effort adjustment knob and a Venturi-Initiated Vacuum Assist (VIVA) dive/pre-dive switch. Definitions please!

  • ·      Techno-polymer – any plastic material used to fabricate something usually made of metal.
  • ·      Inhalation effort adjustment knob – The knob on the left side of the regulator used to adjust the air flow.

These allow for the user to breathe dry and easy, regardless of depth or position in the water.

Okay, as always, I’m leaving the technical details to the professionals…. [Me] Tag out, [SCUBAPRO] Tag in

MK21 First Stage:

  • Air-balanced flow-through piston provides constant and effortless airflow unaffected by depth, tank pressure, or breathing rate.
  • Polished chrome plated marine grade brass body is close to 20% smaller than the MK25, making it an easy travel companion.
  • Unique thermal exchange design with external fins optimizes freezing resistance.
  • Two high pressure ports, one on each side of the body, allows the first stage to be positioned either up or down.
  • Standard “smart” hose routing cap offers four low pressure ports angled for more convenient hose routing (+/- 20º).
  • Optional hose routing cap increases routing configurations with four angled low pressure ports (0°/30°) plus a fifth centralized high-flow low pressure port.
  • Redesigned yoke allows for easier mounting on a cylinder, and redesigned cap protects internal components from water intrusion after the dive.
  • Available in either 3364psi/232bar INT or 4350psi/300bar DIN configurations.
  • Weight: INT 232 (oz/g): 27.5/780; DIN 300 (oz/g): 19.7/560.
  • Airflow at 2900psi/200bar: (l/min/SCFM): >7500/265.
  • Intermediate pressure (psi/bar): 133-142/9.2-9.8.

S560 Second Stage:

  • Air-balanced valve smoothes out the inhalation effort when diving at varying depths and supply pressures.
  • Lightweight techno-polymer casing helps reduce jaw fatigue and improve diving comfort.
  • Technopolymer inlet tube contributes to reliability and long life.
  • High flow exhaust valve reduces exhalation effort to lower overall work of breathing.
  • User controls include a diver-adjustable inhalation effort knob and Venturi-Initiated Vacuum Assist (VIVA) dive/pre-dive switch.
  • Super-flow hose features an oversized bore (larger inside hose diameter) that allows more air to flow on each inhalation.
  • Ultra-comfortable orthodontic mouthpiece is easy to grip yet doesn’t inhibit airflow.
  • Weight (without mouthpiece): 5.6oz/160g.
  • Airflow at 2900psi/200bar: 1850 l/min – 66 SCFM.

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