Face Mask Northern Mockingbird. Reusable Cotton Face Mask, 7 ½ X 4 ½”. These masks include a PM 2.5, which may already inserted into the mask . Our masks stack multiple layers of material, 95% Polyester and 5% Spandex; interior is soft 100% pre-washed cotton. The CDC has adopted a safety-first policy and is recommending everyone wear non-medical protective face coverings to help "flatten the curve"