The Holton Model TR181 Bass Trombone is in the key of Bb. .562" bore, 10" hand-hammered red brass bell, chromeplated nickel-silver inner slide, nickel-silver outer slide, traditional wrap with F tuning and G/Gb slide, inline independent dual triggers with ball-and-socket linkage, lacquer finish. Holton includes mouthpiece and deluxe wood shell case with the TR181 Trombone.