Flexitubes are injection-molded, not extruded. Junction tubing is not required. Flexitubes incorporate the hook holder (40mm/1 1/2" long .08 I.D.), and don't require cutting and fitting different sizes of tubing together. The thinner tube at the front end (40mm/1 1/2" long .08 I.D.) will accept 3/32" HMH Cone Heads, and the length of either end can be trimmed with scissors to individual needs. Either of these two lengths offer maximum, unlimited versatility.