Extra depth allows for storage of larger, bulkier supplies. Use "Open Core" (without dividers) for quilt squares, works in progress, patterns, books and more. Customize using dividers for Charm Packs, Fat Quarters, Layer Cakes, etc. Also accomodates the New 6901AB Thread Tray! 15-1/4" x 14-1/8" x 6-1/4".