The VMAC (VORTRAN Medical Air Compressor) is a 50 PSI compressor that runs on a standard AC outlet and can power respiratory devices such as the VORTRAN PercussiveNEB 2.0.  It is designed for patients to be able to use their therapy devices at home.  Just connect your PercussiveNEB 2.0 to the compressor's DISS outlet and power on - no adjustments required.