Found one of these on eBay last night. Buy it now so I did after some very limited research. They apparently are somewhat rare and having never seen one prior to last night I believe they are at least uncommon.

I was able to locate several examples, all on auction sites and they seem to bring some big bucks.

But not one of the sites really had any information on them. It is a large canteen with a screw on cup that covers the cork. Earliest example I found was 1942. latest I believe was 1966. The one I found does not have it's cover which all the others did. Has a canvas cover with a top with three snaps on each side.

Based on the name, I would assume it's an issue item to battlefield medics which is why the larger size and the cup.

https://i.ebayimg.com/images/g/pm4AA...~H/s-l1600.jpg

https://i.ebayimg.com/images/g/YpUAA...~N/s-l1600.jpg

https://i.ebayimg.com/images/g/M7IAA...~R/s-l1600.jpg
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