The Light Cahill fly pattern is a universal trout fly with many uses. In the colder winter months, tie one of these fishing flies onto your line in a small size #18 or #20 for those small winter hatches. In the late spring months, these flies are effective for trout in larger sizes #12-#16. With the parachute style horizontal hackle, these fishing flies will float lower on the water however are still very visible on the drift due to the light colored body. Be sure to have a few of these in your box in a variety of sizes for applications throughout the year.