[SIZE]Air Purifiers replacement filter element(2.56 x 2.56 x 3.74 inch). [FILTER COMPOSITION]pre-filter layer, HEPA filter layer and activated carbon filter layer. [FUNCTION]This filter helps to purify pollen, smoke, pet dander and PM2.5 Micrometre air pollution in the air. [REPLACEMENT CYCLE]It is recommended to replace the air purifier filter elements every 3-6 months. The service life of the filter depends on the operating time and existing air conditions. colour: White Material: plastic Package Contents: 2 x Air Purifiers Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. [SIZE]Air Purifiers replacement filter element(2.56 x 2.56 x 3.74 inch). [FILTER COMPOSITION]pre-filter layer, HEPA filter layer and activated carbon filter layer. [FUNCTION]This filter helps to purify pollen, smoke, pet dander and PM2.5 Micrometre air pollution in the air. [REPLACEMENT CYCLE]It is recommended to replace the air purifier filter elements every 3-6 months. The service life of the filter depends on the operating time and existing air conditions.