Aerostar 16 3/8 x 21 1/2 x 1 MERV 6, 12PK

Nominal Size : 16 1/2x21 1/2x1; Actual Size: 16 1/2" x 21 1/2" x 3/4" This MERV 6 filter is comparable with MPR 300 & FPR N/A; Designed to filter microscopic particles such as lint, dust, and pollen Simple to install and a cost-effective step towards a healthier home environment. For best results, change your filters every 60 to 90 days but increase frequency to 30 days during peak summer and winter months 100% synthetic electrostatic media for high efficiency with low air flow resistance Manufactured by Filtration Group, a world-leading manufacturer and supplier of filtration solutions making the world safer, healthier & more productive