PowRyte 2-Piece HVLP Gravity Feed Air Spray Gun Kit HVLP (High Volume Low Pressure) technology provides a higher transfer of materials while reducing bounceback and overspray. Suspension hook enables easy storage Built-in 3 control knobs: Fluid control regulates amount of paint sprayed, Pattern control adjusts the fan pattern size, and air adjustment valve provides versatility to adjust air flow Filter ensures clean paint, helping you get the best end result 20 oz. large gun: Working pressure 30-45 PSI, Nozzle size 0.055 in. /1.4mm; 4.2 oz. small gun: Working pressure 20-30 PSI, Nozzle size 0.0315 in. /0.8mm.air compressor needed