The Light Cahill pairs perfectly with its dark counterpart. This fly is many things; a mayfly imitation, a caddis imitation, and overall, a trout catcher. Its profile is so iconic because of how effective it is. Slow to medium water during just about any hatch will trigger bites. A great set up with this fly is tied as a dropper below a Dark Cahill. This is a great exploratory fly to see what trout are keying in on.