This is an original XM28 “Tunnel Rat” / “Grasshopper” gas mask, produced by Mine Safety Appliances (MSA) and dated 1969. Designed for use during the Vietnam War, the XM28 was developed as a lightweight, compact riot-control mask for troops operating in confined spaces and jungle environments — particularly tunnel rat units and military police exposed to CS and CN tear gas.
 
Nicknamed the “Grasshopper” for its insect-like appearance — with twin translucent cheek filters resembling compound eyes — the XM28 was a far departure from the heavier M17 series masks. Its low-profile design, lightweight build, and flexible rubber facepiece made it ideal for soldiers who needed mobility and visibility in tight quarters.
The “Tunnel Rat” moniker originates from its occasional field use among U.S. tunnel exploration and clearance units, who prized its minimal bulk and ability to fit inside the claustrophobic underground complexes found throughout Vietnam. While not rated for full chemical warfare protection, it was perfectly suited for riot agents and smoke used in the tunnels.
 
This example is a Size Small (S12) mask, stamped “69 MSA”, and remains in excellent collectible condition. The rubber is still supple, the harness straps are intact, and the internal valves are present. It includes a period-correct M9A1 Field Protective Mask carrier, which, while not originally issued with the XM28, is authentic to the same era and serves as a fitting companion for display and storage.
 
A rare and iconic piece of Vietnam War experimental equipment, the XM28 is prized among collectors for its unique design, limited production run, and association with specialized troops in one of the war’s most dangerous assignments.
 
For display and collection only. The filters are obsolete and non-functional for protective use.