I’m currently using the MSR MiniWorks EX and it’s a great pump filter. It delivers a lot torque on the lever and can fill up an empty Nalgene in just a few minutes. However, it’s relatively expensive ($90 on REI), large, and weighs a ton by ultralight standards. 460 grams (about one pound) may not seem like much on its own, but when the goal is a sub-20 pound pack, it just won’t do.
So I ordered the Sawyer Squeeze filter system on Amazon for $30. Squeeze filters, while requiring more elbow grease, are much smaller and weigh just a fraction of full-size pump filters. A squeeze system also completely changes the way I gather and carry water on the trail. Right now, my gather/carry system looks like this: