Large M31 medical canteen marked ESB 43

Large medical canteen or M31 Labeflasche marked ESB 43 which indicates production by Eduard Sommerfeld, Berlin in 1943. Black Urea Resin (Type of Bakelite) cup marked F7/K. Complete with its supple leather carrying strap which features a faded ink stamp. Beautiful M31 Labeflasche in a good condition!