To use these vintage metal balancing scales, simply place the items you want to weigh on the bowls. Try to put them in the center for accurate results. When not in use, keep them in a dry place to prevent rust. If they get dirty, you can gently wipe them with a soft, dry cloth. Avoid using harsh chemicals as they might damage the metal. Don't overload the bowls beyond what they can handle to ensure long - lasting use.