These were the answer to that annoying little space below our deck.  The opening was just big enough for a dog to squirm underneath the decking.  I foster dogs so I end up with dogs in the yard who might be a little frightened at first.  Invariably, one will get under there and find it difficult to get back out.  I have tried many things to block the way.  This product is perfect and does not look bad once installed.