This is the only one that is 20" in height that I can find at Amazon.I have no problem having it assembled. Once you get the idea of how parts are connected, it's just like playing with Lego.One thing I need to mention that there is no spare part. I have the tips break off on two of the plactic string during installation (pic 2). I wish the manufacturer can put some spare part in the package, especially this piece.Another thing is that the long side is a bit bent once the plant and soil are in place. I have a fear that it will break in the long run, therefore the durability is to be tested.Overall I'm pretty satisfied with this item.
David 
