A 7 inch by 9 inch olive rubber gas mask. The C4 gas mask was entirely designed in Canada. The C4 offers excellent chemical and biological protection. As an addition it is shatter proof, light weight and very durable. This mask also comes with an olive canvas carrying case.

The Canadian C4 gas mask is the current issue respirator of the Canadian armed forces. Manufactured by the Defense Research Establishment of Ottawa (DREO), production started in the early 1980s and the mask serves as an excellent example of the “Fourth Generation Respirator”.

The Canadian C4 has convex dual polycarbonate eyepieces that provide a reasonable field of vision, in contrast to masks with circular flat lenses.

The profile of a more common green C4 gas mask. Note the drinking tube and the head strap.

The mask itself is made of butyl rubber. A voice diaphragm is located beneath the eyepieces, and more modern versions include drinking straws. The filter canisters can be attached on the right or left side, allowing both left and right handed users to sight weapons. Astride of the voice diaphragm is either an exhale valve or an inlet valve, depending on the model. The mask has a six-point fabric head harness, with only two adjustable straps, the adjustable being the bottom ones below the user’s ears.

The C4 surpasses NATO and related Triptych requirements for face, eyes and respiratory tract protection against chemical and biological warfare agents when used with an approved filter/canister.