Greetings.

I must admit, I'm not quite "UL", more of a "pretty damn light (PDL)" hiker depending on destination and motives of the hike.  But I learn a lot from this group/mindset. 

But I stumbled upon this One Bottle Hydration system that I tried and liked it enough to recommend it to a certain niche of hikers like me.  It combines the hydration bladder tube and bite valve with the plastic water bottle approach.  Really is the best of both worlds – convenience and reliability of a 28mm 1L Smart Water bottles (or wide-mouth nalgene 63mm) and the drinking hose from a hydration pack (less the awkward, hard to clean bladder).  If you aren't a fan of hydration bags, hate reaching for the water bottle, don't like your water bottle strapped to your pack strap, and feel like you should be drinking more, its worth considering.

I recently took it on trip to Zion and really liked it, more than I thought I would.   Definitely an item that will go with me on every backpacking trip I think.   It kept me drinking more water and staying better hydrated than I normally would.  Only down side (a good thing!) is I went thru more water than I normally do.  And also kept me from having to reach for my water bottle from my pack's side pockets, which never come out easily for me.

Anyway, liked it enough to consider mentioning it.

Possible negative to UL:  3.5 oz (not an issue for me relative to its advantages).

Positives: just works, adaptable, keeps me drinking, no bladder, small garage-grown single-person manufacturer, fair price, and solved a problem I didnt know I had.

Happy hiking from Ohio

That is pretty neat. I actually like those flip top lids. I have not seen the Nalgene bottles with those lids for sale in quite some time. I think they got complaints about them leaking, but they work very well in an external pocket while hiking where they just need to seal against splashes.

I wish that had a universal adapter that could cennect to the spout in the flip top lid and the Smart water bottle threads.

Another thing to consider is that technically any 3-d printed object is not food safe. The reason is that the manufactoring process creates lots of tine cracks and crevices that can grow bacteria. The Smart bottle cap doesn't have much contact with water so it might not be a problem. I didn't see anything where the guy seals the lids after printing. If he doesn't, you might want to do it yourself. I would recommend a food grade flowable liquid silicone.