The Torretta metallica is one of the most remarkable designs of the Vallo Alpino with its four protruding embrasures. It can only be found in some strategic areas where large scale attacks were expected. Each of the four embrasures has a field of fire of 100°, so they are overlapping. The armament consisted of one MG, after 1940 two MGs were used. However this meant that the MGs could only be used in opposing embrasures. The weapons were placed in a large sphere. By turning the sphere 90° the embrasure was closed. This type was 20 cm thick and could resist medium hits.