The Aprilaire Model 5000 is a complete system. Included is the new One-Touch control, steel frame, the power pack door containing the high voltage power supply, the plastic inner filter housing with ionizer frame and wires, control electrode (prefilter) and 6 pleat spaces (combs). One Aprilaire 501 filter is included. Our photos correctly show the items included.
The Aprilaire 5000 does not include an air flow sensor. The air flow sensor would turn on the 5000 only then there is air flow. New furnaces provide a 120v connection to power an air cleaner only when the blower is running (see the schematic pasted on the inside of your blower compartment). The optional Model 51 could otherwise be used.
The Aprilaire 5000 is rated #1 by the leading product magazine for 3 years running.