This mask was used by the British Civil Defense Service in World War II and was not given to the general public. The mask was made by many companies; Avon, Seibe Gorman and L&Br Co.
The lenses on this mask are kept inside a metal frame which is screwed together on the inside to hold them in place.
The Civilian Duty Mask works like a normal mask and has a 'flutter type' valve. The filter of this mask can be easily removed by removing a clamp and pulling out the filter. Some of the filters on this mask had an arsenic 'pre filter'. This was a green part on the end of the filter which provided extra filtering of gases. Due to the excessive weight of the filter, the mask is pulled forward, proving to be an inconvenience for the wearer.
This mask has a microphone port. Upon addition of a microphone and headset it is identified as a 'Radio Operator' Mask. The microphone was attached by puncturing the rubber port and adding the microphone components. The headset was then attached.
The mask was issued in a small bag with a variety of colours, usually brown or green. The bag was carried over shoulder.For more information and display of masks check out these videos: