Thats not a Conn Stencil I am familir with, but Im not sure as there is a large nuber of Conn Stencils Quickest way to tell is to look at the Low C keygaurd(on the bottom bow of the horn) and if it looks like the Mercedes Benz Logo, chances are its a Conn. If it is a Conn C melody horn, the neck should look like an alto neck, but longer than a normal alto neck. Other Common stencil makers are Martin, and if they made it, it will have soldered on, or bevelled tone holes. This link should help you in determining who made your horn. www.saxontheweb.net/Resources/Stencils.html Read through it, and then you can also go to the site www.saxpics.com and compare your horn to the pictures there. Stencils generally identical to the horns they were made after, just different engraving and unmatching serial numbers. Lastly, if it's about 22" long with the neck attached, it's an Eb alto sax. 28" or so and you have a C melody, 32" and it's a Bb tenor. A straight horn about 25" long is a Bb soprano. Those are the most common...the are others.