Classroom Keepers 15 Slot Mail Box measuring 16-3/8 x 31-1/2 x 12-7/8 inches is perfect for classroom or office use. An easy to assemble, sturdy, corrugated cardboard sorter helps organize a wide variety of school communications. Box with 12-1/2 x 10 x 3 inch slots can store supplies like mail, paper, art and craft or office supplies.