The adhesive stickers available in white on black or black on white. They are applied over a standard MAC (Apple) computer keyboard. They are a larger font size and offer good contrast. If you are a frequent computer user a large print keyboard may be a better option as commonly used letters may wear out too quickly. If you have a laptop the function stickers on this sheet will be too large. Please disconnect your keyboard and clean down with metholated spirits before applying stickers.