The bunker in Piaski was a single-storey structure used for frontal fire. It was to be armed with three sets of NPS-3, an LMG for close defence and an LMG for entry defence, but only two sets of armour were provided for the fortified versions of MMG. Under the combat rooms, there were tanks for empty shells. Unfortunately, they have been flooded by groundwater.

The room of the close defence embrasure has no partitions. The chamber is equipped with an emergency exit under the embrasure and an additional tank.

The bunker belonged to the Duńkowice Resistance Point and was part of the Rawa Ruska Fortified Region of the Molotov Line. The main task of the Duńkowice Resistance Point was to protect the road from Radymno to Korczowa, which opened the possibility for troops to march towards Lwow.