The AprilAire 213 20 in. x 25 in. x 4 in. MERV 13 FPR 12 Pleated Filter is a high-quality air filter designed for use in air purifiers. With a MERV rating of 13, this filter provides efficient filtration to improve indoor air quality. The synthetic filter material and pleated design ensure maximum effectiveness in capturing airborne particles. The filter has a frameless construction and comes in a pack of 1, with a filter life of 12 months. Its white color and electrostatic features make it a reliable choice for maintaining clean and healthy air in your home.