Reusable and Transparent: Made of high-quality environmentally friendly PVC material, transparent as if printed on the keys, removable but leaves no sticky residue and does not damage your keyboards. Universal and Thoughtful: Includes 52 colorful stickers for white keys and 36 tones for black keys, a total of 88 stickers. The keyboard stickers for most pianos include 37/49/54/61/88 keys. Clear and Impressive: The letters on the piano keys are placed under the top layer to prevent the ink from fading. Colorful, larger letters and bold font help children or beginners to familiarize themselves with the keyboards faster, which significantly improves the efficiency of practice. Easy to Install and Thinner Material: The 2 guides in the upper right corner and lower right corner can help you install them in minutes. Piano key stickers are 50% thinner than regular ones. You can barely feel they are there.