1、WIDE APPLICATION: Suitable for all 88/61/54/49 key pianos and keyboards. White key stickers measure 4.0x1.55cm and black key stickers measure 3.9x0.85cm. 2、DURABLE DESIGN: The letters are printed on the back of the clear stickers, so they can withstand the constant impact of your fingers, always clear and never fade. Waterproof, when the surface is dirty, just wipe it with a damp cloth to clean it. 3、NO ADHESIVE LEFT BEHIND: The adhesive on the back is clean and durable and can be removed and applied multiple times. No adhesive is left on the piano keys, completely harmless to the keyboard. 4、FEELS GOOD: The piano key stickers are so thin that you can barely feel them when playing the piano. The surface of the stickers is slippy and non resistant, feels comfortable when practicing slides, arpeggios and other techniques. 5、EASY TO READ: The piano letters are large enough, clear and easy to read, kids are happy to learn piano and memorize the note positions. Perfect for beginner.