The suction cup at the bottom doesnt hold it in place, but I think my shower wall my not be perfectly straight.  I used Sugru moldable glue to keep it from swaying back and forth. I love that this is adjustable, and the handheld showerhead doesnt interfere.  It also holds a lot more than any other shower caddy Ive had.  Ive had this for months, and no rust yet!