These can be used on woolly buggers, streamers and a number of bass, pike and saltwater fly patterns. Flexi-Tails are available in three sizes. *Small work on hook sizes 6-10 and have 10 to a package. *Medium work on hook sizes 2-6 and have 8 to a package. *Large work on hook sizes 1+ and have 8 to a package. The first color is the "Flexi" material and the second color is the Holographic "Flash". All of the colors are semi-transparent except black which is opaque. Pictured: Bass Kicker Diving Frog pattern by Joe Messinger. Made with Yellow and White Deer Hair, Solid Yellow Flexi-Tails for legs, and one of our Pre-Cut Foam Collars. This pattern is also available as a kit that comes with everything you need.