1.Versatile Compatibility: The furnace air filter is compatible with 2 types of standard machines: (1) AC Nominal size: 20H x 25W x 4D (inches), actual size:20.4H x 25.4W x 3.77D (inches), it's a normal HVAC AC furnance filters. (2) After installing the included frame, it fits AirPurifier Models: 1210, 1620, 2120, 2200, 2210, 2216, 3210, 4200, and Space-Gard 2200 with Upgrade Kit 1213

2.Product Specifications: This package includes 2 packs air filters. AC Nominal size: 20H x 25W x 4D (inches), actual size:20.4H x 25.4W x 3.77D (inches), for a long-lasting, durable user experience

3.Performance Specifications: Equipped with MERV 11 furnace filter filtration and aluminum mesh, it effectively improves indoor air quality, helping to maintain a healthy environment