1. Stickers are writable,using a pencil,pen or permanent marker,easy to place on vehicles,however,difficult to remove. 2.These parking violation stickers come with a permanent adhesive that offers great adhesion.The adhesion will get stronger with time,these violation stickers require a scraper to properly remove the sticker after they are stuck onto the glass. 3.These stickers speak louder than words. After you put a few of these on the violators' driver side windows,the trespassers will get the message. 4.These fluorescent stickers are very hard to be removed after affixed on windshields. They are very useful to discipline violators. 5.Each sticker measure 5*8 inch，50 pcs per pack.