Five layers Filter Material: 2*Anti-sticking cloth, 1 *Filter cloth, 1 * Activated Carbon and 1 * Efficientfilter cloth as in picture. Reasonable Size: PM2.5 Activated Carbon Replaceable Anti Haze Filter. Filters size: 12x 8 cm/ 4.7 x 3.1 inches. Wide applications: Activated Carbon Filter anti airborne particlesdust, smoke, pollution, ash, gardening pollen and so on, suitable for most occasions. Replacement Filters, recommend replacing filters once a week for the best effect.