CPC A62B 18/025 (2013.01) [A62B 7/10 (2013.01); A62B 9/02 (2013.01); A62B 18/084 (2013.01); A62B 18/10 (2013.01); A62B 23/02 (2013.01)] | 19 Claims |
1. A mask, comprising:
an outer shell including at least one first opening and at least one second opening;
an inner shell including at least one first opening and at least one second opening, wherein the inner shell is nested within the outer shell such that the at least one first opening and the at least one second opening of the inner shell substantially align with the corresponding one of the at least one first opening and the at least one second opening of the outer shell;
a first filter fully overlapping the at least one first opening of the inner shell and the at least one first opening of the outer shell; and
a second filter fully overlapping the at least one second opening of the inner shell and the at least one second opening of the outer shell;
wherein the inner and outer shells each comprise a transparent forward panel.
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