Copiato da mouthpieceexpress:
LARGE Morse taper
Commonly known as Standard Taper. Fits all Yamaha, Getzen, Jupiter, Callet, Stomvi, Benge, King, Blessing, Conn Vintage One, Weril, Holton, Schilke, older Kanstul 1525 flugelhorns, Austin Custom flugelhorns, Allure, Jupiter, and most other “American” flugelhorns except Bach.
SMALL Morse taper
The so-called "Bach Taper." Fits Bach, Courtois, CarolBrass, LeBlanc (including Sandoval), B & S, Taylor, and some other European brands, plus Kanstul models 725, 1025, and newer 1525.
FRENCH (straight) taper
Also known as Couesnon Taper, French taper is used by original Couesnons, Flip Oakes "Wild Thing," Kanstul CCF 925, and original F. Besson flugelhorns.