No More Excuses! Pencil clip allows you to keep a pencil handy at all times for marking your part. Fits any tube with a 24 to 26 mm diameter (15/16 to 1-1/32 inch). Useful on orchestral music and microphone stand mainshafts, as well as bass trombones, baritone horns, euphoniums, and tubas (plus Edwards/Getzen large bore tenor trombones). Holds a standard wooden pencil.