The San Juan Worm is a must-have fly pattern, as it imitates the aquatic worms that occur naturally in most trout streams. The White River Fly Shop Masters San Juan Worm Fly-Tying Kit contains all materials needed to make 20 great-looking worm flies and includes easy-to-follow, full-color step-by-step tying instructions just add vise! Kit contains:1 spool tan UTC 140 thread, 20 #8 hooks, 10 Ultra Chenille (1 ea. of 10 top colors). Cancer and Reproductive Harm- www.P65Warnings.ca.gov.