Lloyd ward wrote a review of MSR HyperFlow Microfilter on November 12, 2010
My experience with this pump has at first been great but that was short lived. At first i thought that it must have been a recalled filter but after my last four day trip with a new filter from campmor the same result. All directions were followed and the same frustration, slow to no water and the back wash didn't even work after eight liters. Do a yourself a favor and DO NOT BUY! or you could just bring a lot of fuel to boil water or stick to the tried and true iodine.