Warburton Tenor Backbore 2 ST large
Warburton Tenor Backbore 2 ST large, Backbore for Tenor Trombone, Symphony tenor, With large shank, Standard model, Ø 6.76 mm bore, Silver-plated, There are three sizes of the ST backbore, numbered from 1-3, with 1 being the smallest and 3 being the largest