Loon's Snake River Mud is a biodegradable sink paste that will help your leaders and/or flies sink. If you've never used a sinking agent like this, try it on your tippet next time you're fishing dry flies over wary fish. It will sink your tippet under the surface of the water and make it much less visible to the fish. It can also be used while nymph fishing on your leader and fly to help get your flies deeper faster. 1/4 oz. tub.