Reusable and Transparent: Made of high-quality eco-friendly PVC material, transparent like printing on keys, removable, leaving no sticky residue and won't damage your keyboards. Universal and Considerate: Includes 52 colorful stickers for white keys and 36 for black keys, totaling 88 stickers. Keyboard decals fit most pianos including 37/49/54/61/88 keys. Clear and Impressive: Piano key letters are placed under the top layer to prevent ink fading. Colorful, larger bold letters and numbers help children or beginners familiarize themselves with keyboards faster, significantly improving practice efficiency. Easy to Install and Thinner Material: The 2 guides in the upper right and lower right corners help you install them in minutes. Piano key stickers are 50% thinner than usual; you can barely feel their presence.