I'm the guy that invented the one that they sell at FTU. It is called The Tail Tamer (rattle shrimp), and I published the tying instructions in Greg Berlocker's book of Texas Fly Patterns. The best place to buy them is I Fly Angler's Edge, located on Post Oak in Houston. They work well anytime shrimp are in the bay - caught numerous small reds on one in Galveston last weekend......