A Hand Switch Lotion Pump acts much like a air suction device that draws the product from the bottle to the consumer's hand despite the law of gravity telling it do the opposite. When the consumer presses down on the actuator, the piston moves to compress the spring and the upward air pressure draws the ball upwards, along with the product inside, into the dip tube and subsequently the chamber. As the user releases the actuator, the spring returns the piston and actuator into it's up position, and the ball is returned to it's resting position, sealing the chamber and preventing the liquid product from flowing back down into the bottle. This initial cycle is called "priming". When the user presses down on the actuator again, the product that is already in the chamber will be drawn from the chamber, through the stem and actuator, and dispense out of the pump and onto the consumer's hand. If the pump has a bigger chamber (common for high output pumps), it may require additional priming before the product will be dispensed through the actuator.