TheAdirOfficeAcrylic Window Sign Holder with Suction Cups (Pack of 2) is a great alternative for posting temporary notices without the need for cellophane tape, masking tape or similar stickums that leave a messy residue on surfaces. Notices or notes easily slip into the side or top of this sign holder. Though firmly attached to glass surfaces with its four suction cups, this sign holder is easily lifted up and off to clean glass behind the sign support. This 8.5-inch wide sign holder is made of 0.125-inch clear acrylic and it comes in packs of two.