The Romanian M74 Gas Mask, which was manufactured in the 1970s, is a fantastic collector's item.
It has two rounded triangular eyepieces, an exhale valve that prevents fogging, an orinasal cup, and is made of chemically resistant neoprene rubber with polymer eyelets.  Comes with a 40mm GOST-threaded filter and a vinyl haversack/carrying bag.
Note: All Gas Masks and Filters are sold strictly for novelty use only. 
*Subject to limited availability