Well, not much to describe other than it's straight to the point: switching between units. If you're working on projects that require jumping between the metric and imperial systems frequently, this add-on makes it simple. Just set your preferred units, assign a shortcut and you're good to go.

1) Choose your preferred metric unit: Adaptive, Kilometers, Meters, Centimeters, Millimeters, Micrometers
2) Choose your preferred imperial unit: Adaptive, Miles, Feet, Inches, Thou
3) Set your shortcut