What are the differences between Jiggs pBone and pBone mini?

The specifications of both are on this site.

Essentially Jiggs pBone is a ‘normal’ tenor trombone in Bb. It is exactly the same in use as the majority of medium bore brass trombones.

pBone mini is an Eb alto trombone. This means that is smaller and higher in pitch. It’s great for existing trombone players to explore the world of the alto trombone but we also created pBone mini as a terrific starter instrument for small children; the pBone mini mouthpiece is designed to be a good fit for smaller children, helping them get started and hit more notes more quickly.