It weighs in at about 6 oz. I've used this a few times and really like the versatility. By using the Gravity Kit, I could filter, without pumping, at about a liter and a half per minute. It made the camping chores much nicer... The benefit of going with the HyperFlow and the Gravity Kit is simply having many options. The fact that the HyperFlow will filter at 3L per minute when pumping and then having the Gravity Kit for basecamp purposes makes it very desirable. What I would recommend is carrying the pump and letting a fellow backpacker carry the gravity kit. It's also great knowing that I own a pump filter that will also gravity feed faster than most pumps!