Nicely engineered wine rack.  The wood was clean and finely sanded, in fact, it was so nice I decided to keep the natural wood look.  I had no problems with assembly.  Just line up the notches and lightly tap them into place with a rubber mallet until fully seated.  I purchased 4 units and stacked them 2 high and side by side.  The racks were stable but as an extra precaution I anchored the upper most cross piece of each double stacked unit to the wall.