MSR HyperFlow Gravity Kit
Price Paid: $80
This gravity system is awesome. I purchased this to go along on my recent trip to Olympic Nat'l Park for 5 days with a couple of friends. The $80 was for the bag and filter kit, everything you need minus a drom bag. I was sick of getting into camp and spending my last few hours of daylight pumping water, or spitting silt out while tabbing. I already had a 10L Drom bag from MSR and this attaches right to it or right to wide mouth Nalgene bottles.
Once in camp, I could walk to the nearest water source fill the 4-5L bag, attach to the drom bag and let gravity do the work, while I got my tent and the rest of the camp set up. In about 8 minutes we had 5 liters of filtered water. I would fill it up once more and top off the drom (10L) and had water for dinner, clean up, drinking, and refilling Nalgenes in the morning for 3. The pump or tabs were fine for water on trail, but this is a camp necessity from now on. It is well worth the few ounces it weighs.
I definitely recommend this to all trail weary backpackers at the end of a glorious day. Even got to take a cold swim while water was filtering.