Using the Cartesian Diver Fizz Keeper Pump Cap, take the squeeze out of your Cartesian divers! Simply screw the pump cap onto the bottle, pump the cap a few times, and watch as the Cartesian divers sink to the bottom of the bottle!
Take the squeeze out of your Cartesian divers with this easy-to-use pump cap, commonly known as the Fizz-Keeper. Simply screw the pump cap onto the 2-liter bottle, pump the cap a few times to change the pressure in the bottle, and watch as your Cartesian divers sink to the bottom of the bottle—no more squeezing needed.