The Fins
The two rear tabs have been specifically designed to ensure proper hand posture, providing a secure grip and thus allowing the fingers to be positioned correctly.
The Keys
The upper part of the flute features a flattened section in the curve of the conical tube at the keys, making it easier to cover the holes.
References
On the back of the instrument, at the junction between the upper part and the main body, a small recess serves as a reference point for proper alignment between the parts.

