Historical information
This filter is part of a complete set of a German gas mask dating to the First World War. This may have been a spare filter which was attached to a mask.
Physical description
Metal cylindrical filter with removable screw on lid. Lid has perforated edges presumably for grip and a cast inscription on top. Lid twists to remove and gives view of interior filter of wire mesh and other material. This section in turn screws onto mask. Base of filter has mesh layers of varying sizes and appears to have once had a paper cover which may have been torn off upon first use; small pieces of paper still attached.
Inscriptions & markings
Engraving on lid reads "GJB".