Cannon

Mounted cannons were the mounted version of regular cannons, and were situated on walls and towers.

Monteriggioni
Some time at the end of 1499, Mario Auditore upgraded the arsenal of Monterrigioni, adding these mounted cannons to the walls of the town. Anticipating an attack from the Borgia, Mario rigorously trained his men in their usage.

A few days after their installation, Ezio Auditore da Firenze, along with Monteriggioni's mercenaries, used these cannons to repel the Borgia's forces after they had begun a siege on the town.

Rome
These cannons were also frequently used in the army of Cesare Borgia. Both the normal and the sea variant were used in his armada.