Compatibility: This replacement filter set only compatible for Molekule Air Purifier, NOT compatible for Molekule Mini, Mini+, or Air Pro Advanced -Filter: Our replacement filter for Molekule Air uses Photo Electrochemical Oxidation () which effectively attach airborne pollutants for air quality improvement. Recommended replacement for average use: every 6 months True HEPA Filtration System: Used with H13 True HEPA layer and effectively attach 99.97% of airborne particles as small as 0.3microns, includes dust, smoke, pollen, pet hair and dander and etc Carbon Pre-Filter: Effectively attach larger particles like dust and dander, while slowing down VOCs on their way to the -Filter. Recommended replacement for average use: every 3 months 2 in 1 High-efficiency Filter: To Keep your machine at optimal performance, please replace the filter regularly. (The printed words may be different, but it does not affect the use) Color: Grey Material: Cotton Package Contents: 1 Pack * -Filter 2 Pack * Pre-Filters 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.