US MIAI-IV-III Army Service Mask 

🇺🇲 United States MIA1-IV-III Service Gas mask size 2 dated July 23rd 1929
The MIA1 started development in 1928 as a means to improve upon the earlier MI Service Gas mask by introducing threaded lenses, newer filters, and arguably, a much better carrier
This mask is in absolutely mint condition given that it is 94 years old. It must have just been opened before I bought it, which is unfortunate given the scarcity of unopened MIAI masks currently.
This particular mask came with an MIV Carrier, MII filter, Packing slip, faceform, and an exceedingly unobtanium T-Type Anti Dim Stick, which is unusual as most Tissot Anti Dim Sticks would usually state they were for Tissot masks, and not abbreviate the word Tissot.
This mask differs from the later MIA2 Service gas mask in that it uses a Red-Brown Gum rubber facepiece as opposed to the Black rubber MIA2 facepiece, and that the MIA1 was made with a sizing system as opposed to the Universal Size on the MIA2
I chose not to use the original harness for this mask given the overall condition of the elastic in the straps, though the harness is not all that different to the later MIA2 harness.