XM28E4 gas mask, most famously used during the latter stages of the Vietnam War, was meant specifically for riot control agents as a much lighter alternative to the M17. Most famously in
XM28 Riot Gas Mask - MACV-SOG: A Unit of Modern Forces Living History Group
How NOT to design a Gas Mask - YouTube
US M17 A2 Gas Mask MSA w/ Filter Canvas Bag Size Medium | eBay
XM28E4 Grasshopper gas mask - YouTube
XM28E4 | Gas Mask and Respirator Wiki | Fandom
3D model XM28 Gas Mask VR / AR / low-poly | CGTrader
remoaner flowers on Twitter: "looks like an xm28, America's most 'are we the bad guys' mask" / Twitter