Good and handy
This is a very handy tool to tune drums.
Instead of spending a very long time to have a decent tuning, it gives a really good tuning.
The main feature for me is that it enables to have an uniform tension over the drumhead.
This gives a much better sound.
It doesn't work well with all heads though...
On a double ply coated snare head it does not detect lower tensions.
Still a great and handy thing to have.