Seated Round Bucket Balance and Hanging Bucket Balance have adjustment knobs for pre-cise measurements; and Iwo interchangeable buckets that are easy to clean and fill. The transparent buckets also allow the child to see what's inside. They are great tools to teach the concepts of number, weight and balance. Children can learn basic math, logical thinking, observational skills and decision making Hanging Bucket Balance has deep calibrated buckets that keep the contents safe and hold up to 1 liter of liquid.