There are these as well and they don't come from half way around the world.
InnerAirLock,LLC...
From what I understand they use a replaceable inner tube where as the Stauns do not
I'm running Inner Air Locks. I started watching them as a company when they came on for a year as a vendor here on RME. When I finally got around ordering a set they sent them out pretty quick and had great instructions. I ended up using more talcum powder than they provided but they went on easy and seem to be really nice quality.
I only have a couple trips on them so far but I don't anticipate having any issues. Just make sure you check the pressure on them before you head out on your first trail. I forgot to double check pressures and ended up with two front flat tires... completely my fault... but the inner air locks made it easy to get back up and going once a guy with an air compressor came to help.
The only annoying thing about them is that if you want to air down before a trail and air-up, it's not very easy to do without letting some pressure off the air locks before hand. If you plan on retaining a single pressure at all times then it's no big deal. The valve stems come grooved to help with this, but it's not very effective.