Conn 8DS CONNstellation Series Double Horn, Nickel Silver Screw Bell 8DS CONNstellation Series Double Horn Nickel Silver Screw Bell The Conn 8D is one of the most popular double French horns with professional players This 8D F horn features a 12 25 large throat bell and nickel finish for a more open, dark sound with a subtle response plus a 468 bore designed for excellent control and intonation