Development of the XM28 mask began in 1966 when the 1st Cavalry Division requested a compact lightweight protective mask for use by combat personnel in forward areas.1 In addition to its weight and bulk, the sophisticated M17 mask was typically carried on the leg, which made the filter susceptible to water damage.
As a result of the request Edgewood Arsenal produced two prototypes for evaluation in Vietnam:
The 1st Cavalry and 1st Infantry Divisions tested the new masks in 1967 and whilst the XM27 was quickly rejected because of its bulk, both units accepted the XM28.2 Consequently production of the new mask, which was manufactured in small, medium and large sizes, began in 1968.3
- XM27 - Identical to the M17 except that the face piece was made of silicone rubber, which allowed it to be folded into a compact package. It weighed 2-1/2 pounds when packed in its waterproof pouch.
- XM28 - An entirely new foldable mask made from silicone rubber that featured cheek pocket filters. It weighed only 14 ounces when stored in its waterproof carrier and was designed to protect against riot control agents (RCA) only.
1. ENSURE 135 (Lightweight Protective Mask)
2. The XM28 was effective against RCA only and therefore was not a replacement for the M17.
3. E135, ENSURE, Records of the U.S. Army Concept Team Activity, Records of the United States Forces in Southeast Asia, 1950-1975, Record Group 472, National Archives at College Park, MD