This manual is published for the information and guidance of the using arms and services and all personnel charged with the issue, alteration, repair, and testing of gas masks in the field. This manual explains the designations or numbering systems for the principal components of the gas mask. In order that confusion in storage records and inspections may be avoided, tables giving the main distinguishing characteristics of the various components are furnished. The several special masks or respirators, canisters, and like equipment are also described. Field repair and testing equipment are listed, and directives for these repairs and testing procedures are provided.

"October 9, 1941". Supersedes TR 1120-35, October 21 1930. Copies 2 and 3 are microfiche copies.