The Winix 115119 Replacement Filter Set P/Size 21 comes with four antimicrobial carbon filters good for 1 year of operation. For optimal performance, it is recommended to change the Carbon Filter once every 3 months.

Designed for use with Winix Air Purifier unit 5500.

Approximate filter size is 16.4"(H) x 12.5"(W) x 1.3"(D)