French A.N.P. M-51/M-53
The French A.N.P. M-51/M-53 was a slightly upgraded M-51, the main difference being the speech diaghram. It was used by the French military until it was replaced by the ARF-A in the 1990's. This example was made sometime around 1953.
A.N.P. = Appareil Normal de Protection = "Normal Protection Device"