I bought this after hearing the high reviews and took it out on a loop around Mt Hood where I had to rely on this filter for a few days. Thankfully I brought my purification drops as a backup, because after my first use, the sealing ring fell out of the tube. This happened every time I tried to attach the filter to the bag, and also resulted in an improper fit. Other than the sealing ring not properly securing into the filter, the screw also did not tighten all the way to the base of the bag. This also resulted in an improper seal, and allowed sediment and other unfiltered water to escape from the filter and into my water reservoir, effectively negating the purpose of the filter in the first place.

I would not recommend this filter, and will be looking to another brand in the future.

This is a great option for a light weight, compact filter!

I was looking for a new backpacking filter. I have used various gravity and pump systems in the past and wanted something smaller and lighter fit in my pack. I do not expect to use it on top of a water bottle as that seems slightly awkward to me.

I was a little concerned the first because I thought it would only work as a squeeze system which as some note seems like it could be a little slow or awkward at times. Having used it as a squeeze filter with the supplied bag as well as with a platypus bag, I was satisfied with the speed and ease of use when squeezing. However, I think this filter really shines when used as a drip system (See attached pictures).

I used it with a 1 liter platypus bag and I found that I could hang the bag with the filter on it from a cord with a tarp clip and let it gravity filter into a Nalgene bottle. If I position the lower tip of the filter just inside the rim of a Nalgene bottle the wind can't blow it off target and I can do something else while my water filters. 1 liter filters pretty quickly and it's much more convenient than holding it. I simply keep the filter, backflushing syringe and the Platypus bag with some cordage in a pocket in my pack. I have the cord tied in a loop with a taut line hitch so I can quickly adjust the height of the filter when I throw it over a branch so that the filter hangs just inside the top of the bottle.

I found the flow to be quite adequate as you may be able to see from my pictures. I back flushed after the first use as recommended and then about once a day on the trail after that.

Regarding the issue that some have had with leakage at the threads, I did have some trouble the very first time I tried to attach it to the supplied the bag and also to my platypus bag. I found it had to be careful to make sure the threads were going on straight and not at an angle. Once I got it lined up correctly, it went on very easily every time after that with no leakage. I have used it for several gallons of water on the trail now, averaging 5 or 6 litres per day for drinking and cooking.

This product has everything needed to simplify hiking and carrying water. As a nurse, the dialysis system of water filtration made perfect sense. I bought it for my son, with a platypus 2 liter bag, to hike the PCT in Oregon. I thought it was brilliant. And it is. Except that on day two of his hike the O ring to create a seal transferring water into the reservoir- broke. Other PCT hikers were familiar with the problem on the mini. Apparently the regular size Sawyer filter does not have the same problem.
Sawyer company- fix your O rings on the mini and you go from a 1 star to a 5!

The gasket that forms a seal between the filter and the bag failed after the first few uses. This caused the dirty water to leak out when attempting to filter it and rendered the device almost useless. Attempted to contact Sawyer with my defective product but have not received a response from the company.

I didn't buy this on Amazon but wanted to give a review anyway.... This is great, my water tastes so much cleaner. I almost didn't get one cause I didn't want to give up my CAMELBAK, but I'm glad I did buy it. So if your like me, and obsessed with your CAMELBAK, here's the awesome news... If you cut the straw of your CAMELBAK this water filter fits perfectly (I've attached pictures).