Douglas, E flat tuba, 3 piston, ca.1900 Tag #: 200342 Serial #: Bell Diameter Bore Size Height 11 3/4″ .610″ 32 3/4″ Comments: ” ‘OPTIMUS’ / DOUGLAS & CO. / 7 SOUTH S. / LONDON / E.C.” on bell. Share this:TwitterFacebookLike this:Like Loading...