The Obice Da 75/18 Model 37 or Modello 3 as it named in-game was an Italian anti-tank cannon used in World War 2. The model 37 proven to be very useful against armor so the Italian army deployed it on many fronts.
The Modello 3 can be only seen in the Monte Cassino campaign's second level where Sgt.Baker is tasked to destroy them. He used one of them to destroy an enemy Panzer IV tank. It is capable to destroy a tank with a single round but it's very hard to manouver around. At the end of the level, the player is required to use it to destroy the entrance to the building to liberate the prisoners.