SPECS: Best uses: Backpacking, long hikes DESIGN & DETAILS: Simply screw the connections onto each side of Squeeze filter and insert the filter inline into your hydration pack drink tube (sold separately) With the filter installed this way, you can fill your reservoir with dirty water and drink safe water from the tube When you don't need to filter water, unscrew the connections from the filter and simply screw them together to reconnect the tube - just remember to thoroughly clean a dirty reservoir before drinking from it without your Sawyer Filter