Evans DATK Drum Key

This is a well made product but its accuracy is not always spot on.
More often than not it doesn't make the lugs sound even enough, with further adjustments by ear necessary.
It'll get you into the same general ballpark quickly enough, but further adjustments are always required.
I use it more as a drum key than a specialized tuner nowadays, but there are far cheaper drum keys on the market.

A nice idea of a product, but does not really work well enough in reality.