Yamaha YHR-671 D F/Bb-Double Fre. H., F/ Bb Double Horn, Professional series, Yellow brass bell, M-bell, Bore: 12.0 mm, 4 Valves, Removable bell, Clear lacquer finish, Combines modern features with a traditional horn design, A thicker bell rim and a gold brass mouth pipe were combined to create a nice rich sound and a constant air flow, Nickel-plated rotary valve covers help to maintain the durability of this professional model