The digi tray, also called a data tray or flexi tray, is a hard tray made of polystyrene much like the tray in a standard jewel case. The trays can adhere to most materials such as card, PVC and vinyl but require strong glue or tape in order to fix them to the surface. They are ideal for magazine mounts or presentation packs. A good example of the use of a digi tray is seen in digi paks and their derivatives. The digi tray is available in black, white and clear and in standard CD size (125mm long and 137mm wide) and in A5 (approx 190mm long and 135mm wide).