Shires K Series STBK30 Tenor TromboneSTBK30 The K30 is a tenor trombone that delivers the rich tonal character and dependable response that define the Shires playing experience, offering emerging musicians a truly premium feel. Its 8. 5 yellow brass bell produces a resonant, projecting sound with excellent clarity and warmth, while the open wrap F attachment and rotary valve provide a smooth, even response through the valve register. Low notes speak with ease, upper register focus