Came out to replace the air filters for 3 rooftop systems. The 2 original rooftop units take 2-20x30x2 air filters each and the new Rheem/RUUD unit takes 2-16x25x1 air filters. All 3 systems seem to be operating properly at this time. Next service will be for heating/heat pump maintenance and filter change. No charge due to commercial agreement. No charge due to commercial agreement.