Our co ver is washable and reusable when it getting dirty, 100% cotton anti dust, safty, fashion look.<br>Made of high quality soft and comfortable material, which is breathable but could efficiently protective with valve<br>One size fits, adjustable elastic ear loops, suitable for running, cycling, camping, traveling, climbing, outdoor activities and daily use. Protect you from fog, haze, vehicle exhaust, passive smoking, etc.<br><br><b>Specifications:</b><br>Material: Cotton<br>Size: 21cm*16cm<br><br><b>Package includes:</b><br>2 x Free co ver<br>2x Carbon Filters(5 layers)