Martech 75570 Model 50-WB Waterborne Combo SystemThe Model 50 WB has all the features of a Quality Air Breathing System, Model 50 series system, plus the additional ability to lower the dew point and relative humidity for spraying waterborne paints. It makes sense that if the air is safe for breathing air, then it would be superior spray able air. Add to that, a way to lower the dew point and the relative humidity you have a complete combo system. The convenience of having a solution to comply with