The mine shown in the B/W pictures is the US version, made for the Dutch Indies Army. Almost identical mines were also made in The Netherlands and on the Isle of Java, Indonesia. During the occupation of Indonesia by the Japanese Army, the mines were used by the Japanese and they were used throughout the Pacific. Dutch stocks in Holland were taken and used by the Germans.

The US made mine needed a pressure of 180 to 240 lbs.
The Dutch and Indonesian version only needed 50lbs.

Information thanks to B. Bosman and M. Jochoms.

Mark found some documentation on this mine which surprised me a bit.
The page below came from a 1969 german army manual, the mine was already taken out of the inventory for more then 20years.
This german text is also the first text I found that speaks of an "A 2" designation.