This is a great tool on several levels. For the beginner wanting to establish a solid embouchure, right through to the advanced player using it for a pre-warm up, or maintaining a standard away from the horn, away on holiday for example.
The Buzzard feels like it is slightly centred around a Bb (concert) harmonic series and it feels a little more slotted than another similar product which I own.
I find that I can practice the usual flexibilities, long tones etc, and then make an easy transition back to the instrument.
So, it's a small piece of plastic, but invaluable to me.