Review on 🐬 Upgraded Dolphin Water Bottle Pump - 4 Tubes Included for Easy Fit on 2-6 Gallon Coolers (Except Glass) by John Caldwell

first of all it works. It works exactly as intended. What they don't tell you is that this is an air pump and not a water pump. It pressurizes the bottle you attach it to (the plastic bottle will inflate a bit) and releases air when you release the pump plunger. I'm not sure I would have bought it had I known about it. But it works reliably. One caveat is pushing very hard on the down tube (the one that leads the water in) or it will fall off when you switch water bottles. No big deal, just inform. I personally prefer a water pump over an air pump. The degree of air compression in a nearly empty bottle is significant.