This is pretty much an essential component, if you don't want to be eating dirt when you take a drink. It works, and it's *way* better than what we all used to do before there were such things -- remember when we tied snack bags around the tube with a rubber band? However, the last time I got a Camelbak, the valve cover came preinstalled -- but not this time. I did locate and watch the instruction video, and even so, it wasn't easy to get on (although I did manage eventually). I'm looking forward to the day when this essential component once again comes fitted on the tube, when you buy the bag.