The site at Les Vardes became the location for the only 15cm SK C/28 battery established on the island, despite three being planned. The advanced nature of these guns necessitated an equally advanced rangefinding system, something that the type M132 and M120 was especially capable of. These fortress standard bunkers both shared the same optical equipment, two armored cupolas for observation, and a 5m rangefinder. The M132 also featured a lower floor, which provided accommodation, while the M120 did not. Clearly visible in the design of the bunker, is its naval influence. The sharp point at the front resembles the prow of a ship, and the 5m rangefinder is very similar to those found on German warships of the period.
Immediately after the war, the scrap drive saw the removal of the armored parts of the bunker using explosives, and not too long after (along with much of the Steinbruch site) fell into the quarry and was broken up with explosives. An interesting footnote, is that the bunker broke along the line between the two floors, indicating that reinforcement in this area was minimal.