Complex sentence: The class's primary armament is a single OTO Melara 76 mm naval gun, and additionally has a pair of Oto Melara 12.7mm machine guns, one mounted on each side.
Split into simpler sentences: The class's primary armament is a single OTO Melara 76 mm naval gun. They also mount a pair of OTO Melara 12.7mm machine guns, one on each side.