Pratt PRA0069 100% Recycled Corrugated Cardboard Box, 13" Length x 10" Width x 4" Height (Pack of 25) 100 percent recycled corrugated box for packing, shipping, and storing 32 ECT grade for standard stacking performance Flat rectangular shape fits frames, books, or other flat items Made of single wall C flute corrugated fiberboard with standard kraft color Shipped flat to reduce shipping costs and storage space