Insulated Black Water Bottle

Very happy with the design, the price and that the only non-steel part is a single o-ring, in its standard configuration.

It operates great with the steel cap, however, I think there is what I presume to be a design mistake in the provided sports cap. The purpose of a straw in bottles like these is usually to feed air from the valve to the bottom of bottle when tipped upwards allowing water to flow without choking up or having to be squeezed (which a plastic bottle allows). In this cap, the straw is attached to the mouth-piece which means the bottle *does* choke up when you you lift it, as the water level swishes below the opening of the straw, so you're sucking air. When you can get water out it's difficult to avoid a bunch of air gargling through with it... I had to hold the bottle completely upright and suck water up like slurping a milkshake to consistently get liquid out, except that the short straw bottoms out before the bottle is empty so you find yourself slurping air again before the water actually runs out, with no way of getting at that last inch of of H2O.

Thankfully, removing the straw altogether helps a lot, and allows normal tip-and-sip usage, it doesn't flow freely like a valve-straw might allow, but sucking it through works well enough and there is a straw-less valve to allow air to bubble in and, praise be to the gods, it lets water out, and you can drink all of it!

Anyway thank you for attending this lecture on fluid mechanics! I hope that feedback is…