Product review (5 stars): Excellent - don't know what else to say !
These turned out to be invaluable in laying my new deck.  I don't think without them my deck would have come out half as good.  Amazingly simple idea and in the end HUGE value for money.  Choosing the spacer size to order was the hardest, I found the 13/64 gave me a good spacing to allow for drainage with good visuals.

In usage, I found that spacing out 4 or 5 20' boards worked the best.