I couldn’t wait for the underbed storage to arrive. They arrive in two pieces, you just unfold and slide the bottom in place. They are stackable and have wheels so the are easy to slide right under your bed. They seem sturdy, although I wouldn’t put anything extremely heavy in them. They are approximately 6 inches high, 24 inches long and  16 inches wide. (I added the photo for size). I filled mine with gift bags and wrapping supplies, it’s perfect!