This is a set of two Shinwoo light kits. These LED light kits change colors as the yo-yo spins and fit in a variety of yo-yos. They will work with most Duncan and YoYoJam yo-yos such as the Duncan Panda, Hayabusa, FH2, FHZ, and MG. YoYoJam Journey, Lyn Fury, and Dark Magic. There are probably many more yo-yos these can fit in so if you find one that we don't have listed then let us know and we will be happy to update the website.