Superbone

[2] Conn manufactured them through the early 20th century, and a similar instrument with a shorter four-position slide, the valide, was invented by jazz musician and machinist Brad Gowans in 1946.

[8][10] In the early 2010s James Morrison in conjunction with Austrian instrument manufacturer Schagerl created his own version of a superbone, employing a larger 0.525-inch (13.3 mm) bore and three rotary valves operated by the left hand.

The player grips the valve section with the left hand, which supports the weight of the instrument while the right arm is free to operate the slide.

[12] Early superbones, and the Holton instrument designed for Ferguson (who was primarily a trumpet player), have very narrow almost trumpet-like bore diameters of less than 0.500 inches (12.7 mm).

Later models from Schagerl and Wessex use a larger bore of 0.525 inches (13.3 mm) found more commonly on modern tenor trombones.