Yamaha OEM Silver or Lacquer Pearl Valve Button, 1 each. Tuba (YBB), Sousaphones (YSH), and others. AKA Finger button. Yamaha P/N H1641001 (lacquer w/pearl); H1841001 (Silver w/pearl); H1141011 (lacquer no pearl); H1341011 (silver no pearl). YBB-321, YBB-621, YSH-301, YSH-411, YBB, YEB, & others. 25mm. Contact me if you have questions.