STRONG SUCTION CUPS - These sign holders attach firmly without adhesive tapes or nails, leaving no marks. The powerful suction cups on each corner keep them securely in place on glass surfaces, even with frequent window opening and closing. They won't fall off! CRYSTAL-CLEAR & TRANSPARENT --- Made of premium acrylic, this window sign holder showcases your message brilliantly while protecting it. Its crystal-clear clarity ensures information is instantly visible to passersby, grabbing attention effortlessly. EASY TO INSTALL & REMOVE -- Featuring suction cups design, installation is a breeze! Simply press the suction cup firmly onto smooth surfaces like glass, tile, marble, or metal – it takes just seconds. When it's time to remove your acrylic door sign holder - just lift the edge! It comes off effortlessly without damaging the surface or leaving any marks. EASY TO CHANGE--- This single-piece acrylic sign holder features open sides with a secure bottom pocket. Simply slide your sign in or out instantly through the side – no need to remove the suction cup sign holder from your window or glass! EFFORTLESS CLEANING --- After changing your message, a quick wipe with a damp cloth removes any fingerprints or smudges, keeping your display crystal-clear and ready for your next message! STANDARD LETTER SIZE--This suction cup document holder fits standard letter-size (8.5 x 11 inch) paper perfectly. Great for use in homes, offices, retail stores, restaurants, cafes, churches, hospitals, clinics, schools, universities, reception desks, lobbies, and more! Perfect for displaying documents, flyers, photos, posters, menus, daily specials, schedules, timetables, advertisements, promotions, notices, reminders, and other temporary information. NIUBEE Acrylic Window Sign Holder:Glass Door Sign Holder with 4 Suction Cups 8.5x11 Inch--Window Mount for Displaying Flyers, Notices, Documents and Menus, for Office, Store, Home, Restaurant Use (12 Pack)