The MK.III respirator was issued to the British & Commonwealth forces during the 1920’s/30’s before slowly being phased out and replaced by the MK.IV. This MK.III example does not have its original hose or filter and has been fitted with an industrial air supply hose. This MK.III would have most likely been purchased as surplus by an individual or a company and had the original hose removed and the industrial air hose attached. Whether this upgrade was a one off or a batch is unknown. The mask itself is very hard and fragile which is very common to see in MK.III and early MK.IV respirators. The flexible exhale flapper valve is still intact. This example, like many, has been reused as a training mask. The “D” stamp on the chin of the MK.III stands for “Drill”, meaning for drill use only. 

PHOTO 3: Six women wearing MK. III respirators during a training drill in Melbourne, Australia. (Argus Newspaper Collection of Photographs, State Library of Victoria.)