Equipment Information Screen:
The Equipment Screen is where you can see what items Settlers are equipped with and to equip them with tools, weapons, etc.
(All professions can equip any type of weapons, but only Infantry can equip heavy type armor.)
To equip the items, you need to click Maintain in Inventory option at the top of the window.
The left window will pop up after clicking on “Maintain in Inventory” button. You click -/+ to either add the item to settler or to take it off so that the settler can either have it equipped or unequipped. You can also adjust the total inventory weight limit on the bottom, “Encumbrance.” Be warned! The more materials/items a Settlers carries, the slower they move.