The stuff that winds up in the back of your refrigerator shelves has met its match!  After I cleaned the shelves and disposed the outdated items, I loaded the two caddies with usable items and now when I roll them out I find exactly what I want/need.  The shelf will stay clean, I won't "lose" items in the back of the fridge, and when I want to clean the caddies, I'll just roll them forward.  This system is working beautifully.