In the latter stages of many mayfly hatches, the predominant phase of the bug is its spent position, meaning the bug has died and it lays flat, belly down on the surface with its wings spread. Fish target this phase and you must match it because the fish will not entertain any other stage of the hatch you might be offering. A DFI Spinner is the ultimate hatch match with CDC wings, biot bodies, and articulated tails. Want to finish the hatch with power? Invest in this bug in all colors!!