Let's paint a dirty picture for you. Your hands are greasy, you don't want to dirty the bottle of hand soap, so what do you do? Simply wave your hand underneath this dispenser, that's what you do. Its infrared sensor dispenses liquid hand soap right on the palm of your hand! Holds 16.9 oz. (500ml) of your favorite hand soap, shampoo or any other high viscosity soap. Runs on 4 AA batteries. (Not included.) Put one in the kitchen, bathroom or utility sink as well. You'll wonder how you ever got along without it.