Hot fix crystals are very popular right now. But they can be time consuming to apply or you have to use a ready made design that you can only use one time. With this tray and the instructions, You can use the design over and over again. You can also change up the design just by how you load the tray. This package comes with some starter hot fix crystals as well as a sheet of transfer tape. Color instructions included. See a tutorial of how this tray works in the Free Video section of this website.