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GM 30

The purpose of the facepiece is to protect the eyes and the respiratory organs against air contaminated with toxic agents. It is used in conjunction with an attached canister.

No markings of any significance for identifying the facepiece are present. Manufactu-rer's and goverment markings are present, however, including the size number, which is either 1, 2, or 3, stenciled on the fabric and/or the rubber lining of the facepiece.

There are two general types of the facepiece: the magnetic and the nonmagnetic. The older type, the non-magnetic facepiece, has its non-magnetic metal fittings painted a field gray color, while the newer type, the magnetic facepiece, has most of its magne-tic metall fittings painted a blue color. The blue painted fittings generally include the eyepiece rims and parts of the connecting piece assembly. In other respects, the face-piece are similar, althrough slight changes in the construction of the headharness may be present.

The facepiece is of four layer fabric-rubber construction, the visible outer layer being a field gray, ??arse canvas material, while the visible inner layer is grayish rubber. The facepiece is sewn at the edges and joints, which are covered with rubber cement. The eyepieces are plastic and are held in place by threaded metal eyepiece rims. Spring metal fastening rings hold the anti-dim discs against the inner surfaces of the eyepieces. A suede leather fitting band and a chin strap are located on the inside of the facepiece. The head-harness has seven points of attachment to the facepiece and is made of cot-ton tape and fabric covered coiled springs. A cotton tape carrying strap is attached to the lower edge of the facepiece, while some models may have a cotton hanging tab at the upper edge.

A cast metal connecting piece contains the rubber disc type inlet valve and the outlet valve.* On the inner side of the outlet valve (A) is a metal gauze or screen. The edges of the connecting piece assembly on the inside of the face-piece are covered with a one-piece rubber mold; over the outlet valve on the outside is a perforated grill. The drum (snout) type of canister used with the facepiece is screwed directly into the threa-ded receiver of the connecting piece.

*The oulet valve may be either the old mica, coiled spring type or the new molded rubber type.

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