DescriptionSuper adsorption, fine dust filtration efficiency of more than 90 percent, efficient electrostatic filter cotton, low respiratory resistance, effective protection of dust less than 0.3 micron.Feature-Color: White. - Material: Filter material. - Size: 12 x 7 x 1.8cm. - Four layers of material, efficient filtering. - Large dust capacity, high concentration of dust next can breathe freely. - Low respiratory resistance, effective protection of dust less than 0.3 micron. - Super adsorption, fine dust filtration efficiency of more than 90 percent. - Activated carbon filter cotton is made of five layers with high efficiency. - Warm Tip: Dear buyer, due to lighting effect, monitor's brightness, manual measurement, etc., there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand! Thank you!