Rare (+2) 

The screwdriver can transform into a any tool.

Using an action to touch the item, transforming it into any type of tool of your choice, which you are proficient with it.

You gain a bonus +2 to spell attacks and saving throw DCs of your spells.

Choose a cantrip that you don't know from any class list (Vicious Mockery). For 8 hours, you can cast that cantrip, and it counts as an artificer cantrip for you.