Is it a tuba ?

[Untersatz]

Well, maybe not a whole tuba............but at least 3/4 of one

[windshieldbug]

It's a 'Tuba Tuba Tuba Tuba' that apparently changes key when you convert it to play up on your shoulder

[Dan Schultz]

It's a Blessing and virtually a copy of the old King 1140 convertible tuba. One leadpipe for marching and one leadpipe for upright concert configuration.

Never met either a Blessing or a King version that I liked. Probably OK for making fart noises on the football field or middle school entry level concert band. But... not much good for anything else but maybe parts.

[toobagrowl]

My middle school band had a King 1140 along with one of those old 1/2 size Yamaha top action BBb tubas. We also had an old over-half-the-lacquer-gone Conn 20K and an old completely raw brass Continental Colonial (Conn 14K stencil) sousies. Both of those small 1/2 - 3/4 size tubas sounded like fart cans in comparison to the sousaphones. We preferred the Continental Colonial souzy over the others.
Whaddya expect....those small, 3 valve, small-bore tubas were specifically made for middle school use.
But the fartiest sounding tubas I've ever laid ears on were any of those small 3/4 size piston Yamahas and Jupiters....

[Heavy_Metal]

Looks like the consensus is that it's pretending to be a tuba.