MESH CONSTRUCTION - The pollution mask is made of Nylon which offers excellent permeability. The lightweight air face mask is comfortable, breathable and good to wear in hot weather.PERFECT DESIGN - Anti pollution mask with adjustable nose clip, hanging Ear Design and removable hook & loop Strap, it helps effective seal and prevents fogging, keeps the mask from slipping. The image 5 show how to take accurate measurements of your head size to get your head size and make the right purchaseLOW BREATHING RESISTANCE - Dual one-way discharge valves and mesh material design of the air breathing mask make air resistance smaller without sacrificing filtration.MULTIFUNCTIONAL - The dust face mask filters out 99-percent of exhaust, dust, chemicals, particles, pollen, smoke and fumes. It is suitable for people with pollen allergy woodworking painting mowing running cycling hiking and other outdoor activities.BUY WITH CONFIDENCE - We want you to be as pleased with your purchase as we are in serving you. We understand that sometimes, things need to be tried on to find the right fit. If you find that the masks you've ordered isn't the right one for you, we're happy to full refund or resend a replacement for you.