Effective protection against airborne germs, allergens, dust, & pollution. Each mask contains 1 x PM2.5 activated carbon filter for five layers of filter protection. All masks are re-usable and filters are replaceable. Filters should be replaced regularly (we recommend replacing every 5-7 days under normal use) and more often in dusty environments. - Adjustable ear straps to suit a variety of face shapes and sizes. - Machine Washable (60°C after each use) - 93.9% Polyester, 6.1% Elastane. Not suitable for children under 7 years of age. Non returnable for hygiene reasons.