map Adjustable Cardboard Corner Protector Cardboard Edges Protector 7x7x3cm for Art Packing Shipping Supplies Pack of 40 What is this These are three dimensional shaped packaging edge protectors. Widely used in protecting valuable paintings, artwork, picture frames, books and more, to protect corner from crushing, deformation and breakage. What will I get? Overall Dimensions: 7x7x3cm/2.8x2.8x1.2inch(L*W*Iner Dia); Thickness: 1mm/0.04-inch; Material: Corrugated paper; In the package of: 40 pieces. Are there any advantages of the product? Made of thick corrugated cardboard and provide minimal impact absorption; Has a good toughness, not easy to break. Large quantity. How to use it ? The corner protectors have a cardboard flap on the front. Simply fold along the lines before applying onto frame corners. What should I notice ? All size above is measured by manual, please allow +/-0.1 inch error.