A foot switch is an inexpensive and easy to use device, which allows a scale operator to utilize functions of their digital scale, such as TARE to zero the scale out, with their foot. Since the scale operator no longer needs to push a button with their hand, they can now accomplish more by using both hands for other tasks.
The best way to describe a foot switch is to compare it to the gas and brake peddles in a car. By performing one operation with your feet, you have more control over other tasks. With your hands free, you can weight out items quickly without ever having to touch the scale.
The foot switch is most often found being used with digital scales in the kitchen. Since you don't need to touch the scale, it will help prevent cross contamination of ingredients, while ensuring that foreign substances don't damage the scale. Making a small investment now, can save you from loosing the money you've invested in digital scales for your messy work environment.