Features1. The ultra-fine PM2.5 ultra-clean air dust filter cotton can efficiently filter the extremely fine dust particles in the air (PM2.5 level) to ensure that you get clean air during the use of the ventilator and improve the air quality. 2. The ventilator membrane filter cotton can filter dust in the air. 3. The filter cotton is made of PET ultra-fine fiber. Its material is safe and no peculiar odor. The pore size is specially designed, and the stiffness can ensure that it will not deform under the suction generated by the fan; 4. The product is disposable and cannot be cleaned and reused. The frequency of replacement is related to the environment. 5 If the filter membrane is not replaced for a long time, after the filter membrane fails, the dust cannot be filtered; the large dust particles included in the ventilator may cause the bearing of the ventilator motor to wear, reduce the life of the motor, and increase the noise of the motor. The replacement time depends on the home environment, generally 1-3 months, and the dust can be ejected by hand every week; the color of the filter membrane should be replaced in time. Notice:Actual color may be slightly different from the image due to different monitor and light effectPlease allow 1-3cm deviation due to manual measurementDescription:Size: 5.3x3.5cm/PCS