A dust filter is created in tiny dust and to reduce secondary air pollution. The filter uses a gasket so there is no air/dust leakage. The air passes through the activated carbon and the odor is absorbed into the absorber, bringing , clean, odorless air back into the air you breathe. Block dust and reduce dust damage in sensitive parts of the machine. Eliminate dust, dust , pollen, spores, most and animals. Colour: as shown Material: plastic Size: 10.3cm Package Contents: 3 x filter 3 x filter cotton cover 3 x filter cotton 1 x Cleaning brush Only the above package content, other are not included. Note: Light 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.