An all in one handy dandy mini wrench that is composed of the most common hex cap sizes. Use this to screw your standard 3M hex nuts found on most quads, then flip it over and use it to looses the standard 5M prop nuts. Flip it again and get the 2M less common nuts found on some of the smaller FPV components. NO more need to purchase specialized M socket drivers.
And all around great tool to have in your field kit!