This is my second pair, exactly the same color, style and size as my first pair of Klogs.  Ive had the first pair for several years, and I wanted to purchase a second pair, not because of wear or that they even look worn (and theyve been worn a lot) but because I was afraid I might not be able to replace in the future.  These are absolutely the most comfortable shoes Ive ever worn.  I can be on my feet all day, walking over 5 miles in some airport because of an unexpected layover, and no arch, heel or discomfort anywhere.  Im not sure what the soles made of but Im sure it helps the the all over wearability and comfort of the shoe.