Developed in collaboration with artists, engineers and technicians, the XO 1650D series double French horn is a perfect merger of professionalism and practicality. The XO 1650D features a perfectly centered instrument on both the F and Bb sides for an easy transition without breaking the range. This is accomplished through a special 3D-forming process to make a one-piece F slide tube that eliminates sharp bend and restrictive breaks with multiple pieces to allow notes to slot more easily and improve overall response. The one-piece leadpipe allows for smooth air flow with reduced resistance and superior intonation, while an adjustable thumb lever and finger hook help make this horn ergonomically fit the player for personalized comfort. The phosphor bronze bottom caps on the 1650D horn offers increased resistance to valve wear and corrosion.