Modestone Glowpad Waterproof Notepad - Glow in the Dark SlateThese waterproof Modestone Glowpads feature a glow in the dark slate, conveniently enabling you to record your notes or drawings in dark or low light conditions. Simply place the slate under the sheet you want to write on to illuminate the paper. The Glowpad is activated when exposed to natural or artificial light and has a maximum glow time of approximately six hours, subject to the duration of light exposure. Developed for use in extreme weather