The most luxurious way to wash your hands - touch-free so no germs or smudges are left behind. Fast, precise motion sensor triggers aerate the diaphragm pump to deliver just the right amount of rich, pre-lathered foam. To control the amount of soap desired, position your hand up close to the sensor for a little soap and farther away for more. Refills are easy; just eject the old cartridge and insert a new one. One charge lasts up to 3 months.