- Layers of the filter are mounted at the bottom side of the mask. So there is no direct contact with front side. Besides this front side of the mask now can be covered with transparent shield for visibility inside the mask.
- Filters are placed leaving small space between two filters, so air can be accumlated after first filter before second filter.
- Sponge type material is inserted inside the slot loop of the mask so there is no room for entering unfiltered air inside the mouth and nose part but eyes are only protected by eye protecting transparent shield if necessary it can be design.
- No exhale air accumulated infront of the eyes which means there is no condensation of moisture in the transparent shield infront of the eye, so there is clear vision for the eyes.
- Exhale air is warm and lighter which rises up and passes through the hollow space inside mask and exhausted from the filter mounted at the two sides of frame edges. After testing , if it is necessary to increase the surface area of the filter and filter frame then filter size can be increase in the design