Install Slots
From Star Pirates Wiki
Install Slots are hardpoints on a ship that allow an item to be equipped. Each Install Slot can equip one item. The number of install slots rise by one for every two ship classes (every class for Dreadnaughts).
The total number of install slots and the number of install slots available can be seen in the Ship Information section of the Home menu.
In order to equip items go to the Ship Inventory and click "Install" on the item desired. The Ship Inventory can also save up to four different gear configurations for different tasks. There are two slots available for all captains, with four more only available if you are Notorious.