80 stickers, each measuring 0.55 inches by 0.55 inches, are suitable for the majority of keyboards. If you need personalized shortcut keys or language options, these stickers are an excellent selection. They can be written on with any ballpoint pen, but it's important to note that permanent markers are perfect for these as they will not cause smudging. The adhesive is very strong; nonetheless, it is recommended to meticulously clean your keyboard before applying these stickers. Moreover, they will completely cover the letters, irrespective of the keyboard's color, rendering them ideal for practicing touch typing.