Stomvi VRII Trumpet | Customized by KGUmusic | Serial No. 31152Condition Used Restored Model Stomvi VRII Serial No. 31152 Bell VRII Bellflex Brass Alloy (approx. 4. 88" or 124mm). Bellflex is a proprietary Stomvi brass alloy. Valve Block Original Hand fit Monel pistons. Bore Size Polybore (PB) a varying bore size throughout the horn for fine tuned air column performance. (Often around ML 0. 459" in similar models, but the VRII is specifically listed as PB). Finger Rings KGUmusic Design Heavy Water Keys Saturn