The Spro SB60 Swimbait Tail and Fin Replacement Kit is perfect for when a big fish takes a little extra. We noticed that the swimbait will not swim correctly without these side fins and obviously won't swim good without the tail. The fins keel the bait so it can track properly and entice fish into striking. We glue them on with clear gorilla glue and find it keeps them stuck on well. Krazy glue will also work in a pinch but tends to come off over time.