Filtration Efficiency >> 90%3 Layer dust mask construction:made of non-woven fiber fabric with 3 layer, soft and breathable, provides a effective protect;Elastic ear-loop:masks with good elastic ear-loop, which can be adjusted its tightness; One size for kids (Age 5 – 10)Suitable for personal daily health protection: these masks are designed to keep away smoke, debris, residue and dusts from youShip to the USA only