The emplacement was intended for the 75 mm Canet gun of 1892 model (75/50C). There were two such weapons on the island. This is a standard Finnish minimalism can be seen in this construction.
On the evening of March 4, Soviet troops tried to launch an offensive on Pitkäpaasi, using Fiskar as a strong point, but being exhausted by continuous shelling, they suffered heavy casualties on the approach to these islands and were forced to retreat back to Fiskar.