This design resembles the original mask design, but with some minor changes. While our standard masks have a filter pocket, our reversible masks have filter fabric sewn between two fabric layers. They also have a nose wire, which helps with glasses fogging up and the fit of the mask. A lot of studies have shown that a mix of T-shirt and cotton material is key to a mask that filters out particles. In addition, the same studies show that having a good fitting mask with three layers is even more crucial. With these masks you can have two masks in one! Mask Up America!