This is a barrel for the Eb clarinet. It is 41 mm tall, the measurements are based on my cheap plastic Eb clarinet.
The cutout enables the use of Bb clarinet reeds without the need to shorten them. This is espectially useful if you want to try a synthetic reed from your Bb clarinet on your Es clarinet without destroying the reed.
This version of the file has a sacrificial layer to support the overhang, so it can be printed without supports (however, I would still recommend supports for a better quality of the bottom of the overhang). After printing, remove the inside circle of the sacrificial layer with a hobby knife and sand the edge.
I will try to later upload a version without the sacrificial layer. In case I forget and you want it, send me a message.
The author marked this model as their own original creation.