This is a most interesting Tenor Tuba or Euphonium in Bb - inscribed "Max Kenner- Musik Instrumenten Macher Freiburg". Kenner flourished in Frieburg Breisgau (now Fribourg) Germany in the late 19th century, and was also known as a woodwind and pianoforte maker.  The horn is stubby for a eupuonium (24") but  has a large bell section with minimal flare (9.5 inches).  It plays with a big but mellow sound.  Each valve has an unique tensioning wheel to adjust individual valve action (see pic below).  The nickle silver trim and ferrules further indicate that this horn was made by discriminating craftsmen.