A few weeks ago when we had guests staying at our house, someone (I’m guessing Derek from past experiences) left their toothpaste behind. Maybe we’re behind the times, but I had never seen one of these toothpaste in a pump thingies. So after we finished using it, I had to cut it open to see if my theory on how it worked was correct. Which it was. There is a foil bladder inside that contains the toothpaste. There is also a one way valve on the bottom of the container. Squeezing the container puts pressure on the bladder since the air valve is closed. Then releasing the pressure sucks in more air so it is ready for the next use. Very simple and efficient design. I’m not sure how much more expensive it is to buy toothpaste this way, but it’s a design I like. Sure beats all of the stupid inventions I’ve seen that supposedly help you squeeze a normal tube of toothpaste.