Mmiao Ultra Bright Colorful Glow in the Dark Fluorescent Luminous Butterfly Wall Stickers, Peel and Stick Glow in the dark. Really bright than any others. Need absorb light to glow in the dark. The best way is to install around a light to activate. Easy to apply - just peel and stick. Sheet size: 30CM X 38CM Applies to any smooth surface 6 pieces one set. Two sets or more are suggested.