Filter-regulator, or “piggybacks,” combine the functions of both a filter & regulator. Piggybacks are compact design and most effective when space is a constraint. Heavy duty type -- High Air flow and drain capacity. Transparent water level indicator for easy checking. Suitable for any 3/4" high flow air pressure equipment or system.Filter – Filter water / vapor in order to extend the service life of air tool / air system. Regulator --- can make sure the output/working pressure is in a certain level. Compressed air filters, also known as line filters, remove contaminates from the compressed air leaving a screw or piston compressor, which often has a high water content and concentration of oil or other contaminants. Compressed air in-line filters extend the life of your tools and equipment down stream. Excess moisture collects in the quick release 1/4 turn metal bowl with. Manual drain. FOR REPLACEMENT 5 MICRON FILTER ELEMENTS. COPY AND PASTE ASIN TO YOUR AMAZON SEARCH B01N7VEJ2V