mckesson kids procedure masks meet astm f2100-19 level 1 requirements, and they have a bacterial filtration (bfe) and particle filtration efficiency (pfe) greater than or equal to 95% as well as a delta differential pressure of <4.0 mm h2o/cm. the fun, polka-dotted design pattern on the masks and packaging help kids feel more comfortable with the idea of wearing a face mask, and they are intended as disposable, convenient, single use protection for children ages 4-12 years old with appropriate adult supervision. these unique masks are constructed of a three-layer, non-woven fabric featuring spunbond polypropylene on the inner and outer layers and a meltblown polypropylene middle layer, and their spunbond outerlayer material helps provide protection against fluids (80 mmhg fluid resistance) while their pleated style allows room to breathe comfortably. plus, their comfortable, flat, knitted earloops are made of polyester and spandex materials and stretch for comfort and a custom fit on small faces (130 millimeters) while their shapeable nosepiece forms a snug seal and secures positioning for increased protection.