"BestAir? is dedicated to providing a clean and comfortable indoor environment for everyone. We have a complete array of high quality humidification wicks, air cleaning filters, and many other accessories, which will ensure that your indoor air quality will be the BestAir? that you and your family can breathe. This leading furnace filter comes with an easy installation design. Each pleat is spot glued to hold the filter in place when installing. Our MERV 11 filter traps most particles from 0.3 to 10.0 microns in size and fits Aprilaire & Spacegard furnaces. Measures 20"" x 25"" x 6""; Actual Size: 6 1/4"" x 24 1/2"" x 3 1/8"" Fits Aprilaire? Space-Gard? 2200, 2250 (201) Lennox? PMAC-20C 24"" (without cardboard frame)