Harpoon Designed for Large Fish. New Magnetic Design. Works on Tuna & Marlin. The new magnetic design allows for quick attaching and detaching. Funks new and original magnetic design is used to attach the harpoon dart's steel wire to the pole. You'll never need to worry about losing the dart again. Also, the dart comes out smoothly after making a catch so you can quickly move on to the next one. The new magnetic design allows for quick attaching and detaching. Furthermore, it has excellent power. In addition to the heaviness of steel, which many people are accustomed to, superior penetrating power can be achieved using the end rope.