The Spot Zero SZ Mobile Series freshwater reverse-osmosis system was designed for boats that don’t have the space for a built in Spot Zero system to treat freshwater from dock supplies from all over the world with varying water quality characteristics, pressures and temperatures. And it does all of this in a compact, portable design. The SZ Mobile Series takes water that’s a few hundred ppm typically down to just 10 – 20 ppm, for ultra-pure spot-free wash downs.