Brief Overview[]
The CO-1 was a post-war respirator made by Czechoslovak state-owned company Gumarny Zubri (interwar Optimit). It is often confused with the pre-WW2 FM series masks due to their similarity. The CO-1 was based off the interbellum "Lidová" template which was made famous by Fatra's FM-3, however is easily discernible from such masks, mostly by the lack of an intake valve. It was used as a civilian mask and by Civilni Obrana (Civil defence) units. The CO-1 kit was basic - consisting of the mask, CF-II-50 filter, and anti-fog soap, and one of three possible carriers.
Mask details[]
As previously mentioned, the CO-1 is essentially a downgrade of the FM-3 masks, the main difference being the headharness. A CO-1 headharness was much simpler and user-friendly in comparison to the FM-3 models. The valve assembly is made of black bakelite and is attached to the rubber by a single metal clamp. Moreover, the valve assembly lacks an inhale valve disc, instead the CF-II-50 filter has one. The eyepieces are made of black metal which was crimped directly onto the rubber. Unlike later Czechoslovak models, the CO-1 valve clamp is not protected by a rubber band. The exhale valve is protected by a removable grate which can be unthreaded from the valve assembly. CO-1 grates are left plain, whereas the FM-3s have 'FATRA' on them. Internally, the mask is very simple, featuring no Tissot system (hence the addition of anti-fog soap). As with most Czechoslovak masks, the CO-1 sports a neck strap. The neck strap is made of grey string.
Other Kit[]
The CO-1 came in three possible carriers - A gold-ish metal tin, a cardboard OD green tin very similar to the metal one, or, quite uncommonly, a haversack. The metal tin is quite shiny, for reasons unknown. The tin is has an adjustable carrystrap made of light brown fabric very similar to the one on prewar carriers, and is riveted onto the carrier. It also features a hook that attaches to one's belt, in a similar style to the German WW2 carriers. Metal carriers are always marked on the bottom with a "K132", with the date underneath. The cardboard tin is much simpler, featuring no belthook, leaving the user with just the carrystrap, which is identical to the one on the metal carriers. It is identical in dimensions to the metal one aswell. The haversack features no pockets, and is usually made of blue cotton. A shoulder-strap and waist tie straps were also stitched onto the haversack. Two press-studs were used for closing the haversack.
A small bar of anti-fog soap was issued with this kit, to compensate for the lack of a dedicated defog solution inside the mask itself.
Civilni Obrana Staff Variant[]
A secondary CO-1 kit consisting said haversack, a hose, and an OF-2 filter was also issued. This is most likely the setup for Civilni Obrana Staff Members as the OF-2 filter would last longer in contaminated areas.
Filter[]
The CF-II-50 filter is the one most commonly encountered with this mask. This filter was unusual in the sense that it has an inhale valve disk in it rather than the mask, much like the interbellum masks it draws much inspiration from.