The B&S 50992W is one of the mosts popular F tubas in the US market. It features five rotary valves right with 3B linkages, and larger graduated bore.
Key : F
Bore : .748" - .827" / 19-21 mm
Bell : 16.5"/ 420 mm, large throat
Valves : 5 rotary valves (4+1), 5th valve right hand operated
Features : Gold brass lead pipe, 3B™ linkage system
Finish : Clear lacquer or Silver-plated