I'm not sure what these 5 canteens are.Although similar, there are three different types. They are all made out of aluminum and the two on the right are just slightly taller than the other three. The only markings on them are located on the neck. The one on the left : "BM6", The two in the middle: "D59" & "D63", and the two on the right, both say, "ICO'55/56". The caps on the left three are green and a softer plastic than the right two which are brown and more brittle. I'm trying to figure out if they are military or not and their age (I'm assuming 1950s for the right two & maybe 1960s for the left three? ). I know I've said alot here but if anyone could identify them, I'd certainly appreciate it. Thank you.