The 1602RS Professional Series Bb Trumpet features a .459" bore and a 4.8" one-piece hand-hammered bell for excellent response and tone. It includes rounded and elliptical tuning slides, regular- and light-action spring sets that allow you to customize the response of the instrument to your needs. The 1602S Professional Series Bb Trumpet also includes standard and weighted bottom valve caps so you can add mass to enhance the projection of the instrument.