These Clear Acrylic Window Sign Holders with Suction Cups are very popular for retail stores， schools， and businesses. The high quality suction cups ensure long-term holding power. For best results， apply to a clean， non-porous surface. The sign holders with suction cups are double sided and ideal for glass doors and windows. Easily print your graphic or message and insert into the sign holder to keep it protected from the elements. You can use both sides at the same time to post signage that will be visible on either side of the glass window or door. Simply insert your document on the top or side of the sign holder and swap out easily without taking the signs down. Let customers know you are open and display your store hours on your door entrance. Advertise a new promotion or display important information so your customers can see it on the way in and out of your store. Give directive for delivery and curbside pickup that is highly visible to your customers. These glass mount suction cup sign holders comes with suction cups that have been field tested and proven to hold long term when used on non-porous surfaces such as glass. The new suction cup design is sleek and modern and the clear transparent unit will match any décor. Versatile and easy to use. The sign holder fits a standard half letter paper size and folded printer paper.