Wikipedia
The Superbone is a hybrid trombone. It has the slide mechanism of a standard trombone and the valve mechanism of a valve trombone. Larry Ramirez of the Holton instrument company built the model TR 395 Superbone in the seventies in collaboration with Maynard Ferguson.
Similar trombones combining valves and a slide were mass-produced in the early 20th century, some by C.G. Conn. The best-known of these was the valide trombone—the name is a portmanteau of 'valve' and 'slide'—invented by jazz trombonist and reed player Brad Gowans. Gowans played one from the 1920s through the 1950s, including with Jimmy Dorsey. The Superbone has a different design, including a slide that locks. It became a staple for Ferguson and Don Ellis. A Superbone has three pieces: bell, slide and valve unit. The valide trombone has only a bell and a valve/slide unit which does not lock.
Ferguson used the Superbone on the recording "Superbone Meets the Bad Man" from the Chameleon album. Ashley Alexander's recording " Spring Can Really Hang You up the Most", on his Secret Love album, demonstrates the instrument's flexibility. Alexander played a Superbone (Alexander referred to the horn as a 'double trombone').
One of the earliest recorded examples of the hybrid valve/slide trombone can be found on a Duke Ellington recording, as Puerto Rico-born trombonist Juan Tizol started using it after he joined Duke's orchestra in 1929. Tizol was commonly credited as playing valve trombone. This can be seen in the 1933 film short by Duke Ellington and his Orchestra entitled "Bundle Of Blues".
The Superbone has a fully functioning tenor trombone slide with 7 positions. It also has three valves placed just before the slide, with the valves arranged in the same manner as on other three-valved instruments. The player grips the valve section with their left hand, which supports the weight of the instrument while the right arm operates the slide.