This storage unit came fully assembled and seems to be very sturdy. As a teacher, I used to order from Lakeshore quite a bit, and now as I stay-at-home mom I turned once again to Lakeshore when I wanted a heavy duty shelving unit to house our kids' toys. It stores tons of puzzles, which are now accessible to our children and not hidden away in a closet! The plastic bins (sold separately) really help to organize small toys, such as building blocks and legos. The only negative about this product is that the wood in one of the top vertical separators is splintering / splitting in both places where the bolts lock the screws in place, and I'm afraid one of my children will pull on this and possibly hurt themselves and the storage unit. I would give it 5 stars if not for the damage. Overall it's a great product, but one section of ours was not well-constructed.