Designed specifically for the LED Fan Motor Mask (sold separately), this custom 4-layer KN95 certified filter effectively removes up to 99.979% of fine contaminants over 0.3μm. The first layer is a strong anti-bacterial net, filtering large particles, impurities, and bacteria in the air. The second layer features an activated carbon filter for sterilization and deodorization, capable of absorbing odors from formaldehyde, benzene, and other harmful substances. In the third layer, a HEPA filter handles PM2.5 including pollen, smoke, and dust. The fourth layer is a shielding protection net, effectively inhibiting bacterial growth and releasing negative oxygen ions. Note: Before purchasing, please check with local guidelines and recommendations to see if this product is suitable for your intended use.