A tight backbore with a lot of sizzle and focus. It has just enough resistance to support a solid upper register. This backbore is a good choice for solo and lead parts that need some projection. It has been described by our customers as similar in feel to a Warburton #4 to #5, although not identical. The shank is based upon a #5 sleeve to make sure almost all horns will receive it properly. The throat is a #27. This backbore is available in two blanks. The lightweight blank is less efficient and will have a slightly tighter feel. The heavyweight blank is more efficient and will feel slightly more open.