Pro Sportfisher Hookguides are tapered Silicone hook guide designed to be used with Pro Microtube or Pro Nanotube products. This product essentially "guides" and aligns the hook as well as the ability to add or take away a "hot butt" to the back of the fly. Pro Hookguides are available in 4 sizes (Small, Medium, Large and XL/Predator) and 9 colors (Clear, Black, Fl. Yellow, F. Green, Fl. Red, Fl. Orange, Royal Blue, Pink and Purple). Pro Hookguides are easy to use: Just plug the larger diameter tapered end to the port or back-end of any Pro Microtube or Pro Nanotube. Presto! You have a flexible, durable hookguide for all ring/straight eye, short shanked hooks that are popular today when fishing tube style flies. If you like to fish tube flies with a non-slip loop knot jammed into the tube, don&';t worry, Pro Hookguides are still a great compliment to that style of rigging. Tippet knot will jam just inside the tube in this case allowing the Hookguide to stiffen a good portion of the non-slip loop for less or nearly zero chance of "fouling" the fly. Pro Sportfisher Hookguides are designed to be used with single, double or treble hooks! Pro Hookguide Specs: Pro Hookguide Small...Hook sizes #10, #12, #14 and some #8&';s Pro Hookguide Medium...Hook sizes #4, #6 and #8&';s Pro Hookguide Large...Hook sizes #1, #2, #4 and some #1/0&';s Pro Hookguide xLarge...Hook sizes #1/0to #8/0&';s Pro Sportfisher Hookguide Quantities/Pack Small: 12 pieces/pack Medium: 12 pieces/pack Large: 12 pieces/pack XLarge: 8 pieces/pack