If you worry about the environment as much as your weight, this is the scale for you! Help protect our environment from the hazards of battery disposal with the Tanita HS-302 solar scale. Improperly discarded batteries can contribute to heavy metals leaking into soil, ground water, and surface water. This environmentally- conscious scale incorporates high sensitive solar cells that draw power from sunlight or ordinary household light. There is never a need to buy or recharge batteries, making the HS-302 Solar Scale specially designed for health-minded consumers looking for products to compliment their green home.