GravityWorks™ Universal Bottle Adapter

Fits snugly on my wide-mouth bottles and the flow rate into the reservoir is much faster than I expected, so filling up at camp takes seconds. The threads feel solid and haven’t stripped after a dozen trips now.

The threading is precise enough that I can swap it between my Nalgene and a narrow-mouth bottle without any leaks, which is the main reason I grabbed it. Set-up takes seconds and it fits snugly enough that I trust it on a rocky trail.

Finally, a way to screw my wide-mouth Nalgene straight onto the filter without wrestling with a separate collar. The threads caught cleanly on the first try, and the whole setup feels solid enough to toss in a pack without worrying about leaks.