... workers must accept training before entering our work-shop Tuba SeriesHTL-690Tuba 3 Rotary keys,BbHTL-691Tuba 3 piston ... Junior Tuba,BbHTL-696Tuba 4 piston keys,BbHTL-697Big Tuba 4 rotary keys,BbHTL-6983 piston marching tubaHTL-699Compensation tuba,Bb/F ... keyHTL-699EEb tone tuba,cupronickel tuning pipe High Quality of Instruments ...