The Fulling Mill Slotted Tungsten Coneheads are perfect for adding weight to any salmon tube fly or predator flies. The slot allows for use on most fly tying hooks easily passing over the barb and the bend, as well as tubes. Remember, when tying tube flies with tungsten coneheads, leave a suitable length of excess tubing at the head to apply the conehead, then to complete the fly, carefully apply a small amount of heat to burr the end of the tube and fix the tungsten conehead in place.