FiltersFast Compatible Replacement for Aprilaire SpaceGard 2400 Air Filter -MERV 13 2-Pack 16" x 27" x 6" (Actual Size: 15 3/8" x 26 15/16" x 6") Aprilaire SpaceGard 2400 Air Filter 16" x 27" x 6" (Actual Size: 15 3/8" x 26 15/16" x 6") MERV Rating: MERV 13 Replaced every 6 to 12 months 2-Pack For Added Convenience Made in the USA!