For the first time a tube is made with two diameters in a single piece! The backend works as an integrated hookguide, and the thinner front part of the tube allows the mounting of weights from the Pro Weight system, and of course fits perfectly to all the different add-ons in the system. 14 pieces/package. Note: A Pro Tubefly Needle (sold separately) is recommended for tying with Pro Tubes. These tubes do not set well on most tube mandrels.