Aprilaire / Space-Gard #410 High Efficiency Filtering Media (Single Filter) Fits the following Aprilaire Air Cleaner Model 2400 after upgrading with #1413 Media Upgrade Kit Model 2140 after upgrading with #1413 Media Upgrade Kit Model 1410 Model 2410 Model 3410 (new premium model with electronic control) Model 4400 (old premium model with electronic control) Newly designed media features: Traps and permanently removes over 90% of pollen-sized particles (5.0 microns) and over 90% of mold and spore-sized particles (3.0 microns). Collapsible media with self spacing pleats installs in seconds. Media replacement is recommended after one to two years depending on air flow. SelfSeal dramatically reduces air bypass, improving filter performance. Rated MERV 11 Airflow Capacity up to 2000 CFM Maximum Filter Length – approximately 28″ No pleat spacers – media slides right in!! Instructions: 1). Turn home thermostat mode to “OFF’ and fan mode to “AUTO” 2).