The Blessing Artist B-88 trombone (with F rotor) has a .547" bore that effectively fills the gap between medium-bore and bass trombones within the trombone spectrum. Extremely free-blowing in all registers, quick tonal response and all-around versatility have made this trombone extremely popular in the American school music scene. The yellow brass bell is 8-1/2" in diameter and features a tapered rotor valve. The hand slide is constructed of bronze outer rails and is carefully aligned and hand lapped to ensure the smoothest possible action.