I designed a 3D print file because I wanted to make an Apex Octane mask, and just needed something fabricated from plastic.

 If any of you want to make some replicated "valves" to glue on a cloth mask, here you go.

Please note, these are purely cosmetic and not functional in any way. Resizing/scaling may be needed for individual needs.

NOTE:

Two different files are uploaded with slightly different contours. One is for a more cartoony of a look, and the other is more industrial and "crooked" style. You get both designs with a single purchase (two for the price of one!).