Genuine Aprilaire 401 high efficiency replacement filter. Used the media air cleaner model 2400. The Aprilaire 401 is rated at Merv 10.
The 401 filter is 27¼" long and 6¼" wide with 32 fan-fold pleats. The filter requires assembly with 6 plasitic pleat spacers (not included).
Replacement is suggested once a year or after one heating and one cooling season. Holding the filter up to light will show the amount of dirt. Only the intake side should be dirty, the side of the filter that the air exits from should remain dust free.
The Aprilaire Stock No. 401 was formally the Spacegard 401. Aprilaire is a brand name of Research Products. The genuine Aprilaire 401 is made in the USA.
Each filter is individually boxed as shown in our photos.
The Aprilaire model 2400 can also accept the Honeywell PopUp2400 filter, replacing the 401 filter. Honeywell has designed the Merv 11 Popup filter to replace the Aprilaire 401 filter. The Honeywell filter slides right in to the 2400 steel frame. The Aprilaire plastic housing and pleat spacers are not needed. Eliminating the messy disassembly and assembly of the 401.