Period (or perhaps reproduction) Esbit cookers. The cardboard box for the fuel looks original but the fuel inside is sealed in plastic. The cardboard box still has German soldiers on the side using the cooker and has D.R.G.M, D.R.W.Z., and D.R.P. markings. The cooker itself has a D.R.P. marking.
I have heard rumors that this style is postwar, however I feel there is nothing to indicate that. All of the markings and graphics look wartime to me.