Original Vietnam War-era U.S. Army ABC-M17 Field Protective Mask manufactured by Mine Safety Appliances (MSA) in 1966. This is the original M17 configuration, not the later M17A1 or M17A2, and is marked size Medium.
 
The painted lot number, 2034-66-2102, identifies MSA production from approximately May–June 1966. The molded facepiece marking reads “66 MSA 2E8.”
 
This mask appears genuinely unissued/New Old Stock. Both cheek inlets retain their original protective plastic, the head harness shows no stretching or repeated adjustment, and the interior has no perspiration or facial-oil residue. The filter-pocket closures show no replacement wear, and the presumed original M13 cheek filters remain factory installed and undisturbed.
 
Also included are the original OD canvas M17-series carrier and an unopened replacement set of two cheek filters. The sealed filter package is made from MIL-B-131E Class 1 & 2 barrier material dated June 1972 by Champion Packages Company of Columbus, Georgia.
 
The mask and carrier exhibit normal age and long-term storage effects, including light surface scuffs, rubber bloom, minor lens haze and fading or wear to the canvas carrier. These do not indicate field use.
 
An exceptionally complete, early Vietnam-era M17 assemblage suitable for an advanced U.S. militaria, chemical-defense or gas-mask collection.