100% smelt-oil fish attractant is made from freshwater lake smelt (rainbow smelt). It is highly effective on all minnow-eating fish. It has shown to be effective on most saltwater species as well. In nationwide testing it improved an "average" day's catch by 30%, overall. But on some days it made all the difference. Effective in all seasons, as well and endorsed by the North American Fishing Club and the Lake Champlain Walleye Association. Used by many charter captains throughout the U.S.A. and Canada! Just a couple drops is all it takes and it's effective on artificial lures or live baits as well. Soft plastic baits will readily absorb the oil, for hours of use.