British C2 "Mickey Mouse" Small Child Civilian Respirator
The British C2 Small Child Civilian Respirator used a red rubber facepiece with two small glass eyepieces, and a bright blue filter right below the exaggerated flutter valve. Commonly referred to as British Mickey Mouse gas masks, they were made to look non-threatening for small children during World War II. Both of these examples were made by Avon in 1939.
Similar masks in my collection: U.S. M2-2-1, Russian PDF-D, Russian PDF-Sh
Stamp inside mask "JB 1"
Stamp inside mask "M/39"
Filter stamps top view "MB.39" "G.C.MK.III"