These flies were introduced in response to guide requests for larger flies to target trophy predators. The first fly was the “Kokanee” imitation for anglers targeting mackinaw in western reservoirs. The PERCH Tandem is a must have for trollers in the northern tier of states along the Canadian border. The yellow perch is a primary forage fish in northern waters for trout, salmon and bass. This 5 inch fly imitates an adult perch that hopefully will interest larger predators.