My password is the last eight digits of pi - math waterproof sticker Stock: waterproof glossy vinyl sticker Size: 3 x 2.1 inches This sticker is perfect for customizing your tablet, water bottle, laptop, tumbler..... stickers are permanent, waterproof, weatherproof, and printed on the highest quality vinyl. If using the sticker on a tumbler/mug/cup, please hand wash only.