Aprilaire 2400 high efficiency media air cleaner is a complete system. Includes the steel frame, access door, inner plastic housing, and the 6 pleat spaces (combs). The Aprilaire 401 filter is included. Our photos correctly show the items included. The Aprilaire filter has over 72 square feet of filtering media rated at Merv 10. The filter improves cleaning efficiency over time. The Aprilaire 2400 Whole-Home Air Cleaner can give you exceptionally clean air throughout your home at a very affordable price. The Aprilaire model 2400 was formally the SpaceGard 2400. Aprilaire is a brand name of Research Products. The Aprilaire 2400 is made in the USA. Installation requires connecting to the ductwork. No electrical connections are needed.