It's quite good, but it would need a piece to fit well in the bottle and not move around.
I bought it on sale for 132 UAH. (a little more than $3). Delivered to Ukraine in 10 days. Charged it fully (note that the instructions recommend charging with a current of no more than 2A), placed it on a bottle. It doesn't charge very quickly, but overall it's worth the price. When I was purchasing it, I looked at the reviews, where the main downside of this pump was the 300 mAh battery, which doesn't last long. I took it apart, and inside there is a 14500 battery with a capacity of 300 mAh. But what's interesting is that there's a spot nearby for an 18650 battery. I removed the 14500, extended the black wire, and installed the 18650 that was in stock. I assembled it, and now everything works perfectly and it lasts a long time. It's true that the charging time has increased, but these are just minor issues.
Fits perfectly. You need to place it on a standard bottle cap, then it holds well.
Great pump, I especially liked that the Type-C charging works quickly, the hose reaches the bottom of the bottle, the cap fits tightly, it doesn't fall off or wobble, it pumps quickly, much faster than the previous one that had a micro USB charger. There is a red charging indicator, blue indicator when charged. I haven't checked how long the charge lasts.
The package arrived in two weeks, it pumps water perfectly, and comes with a silicone hose for water intake, although there is no seal for installation on the bottle included, which is a minus one star.