Plantlife Reusable Wool Dryer Balls include six extra-large laundry balls made from premium New Zealand wool. The set contains three white and three gray balls that move throughout the dryer to help separate fabrics, improve airflow, and reduce wrinkles, static, and drying time. These unscented dryer balls can be reused load after load as an alternative to disposable dryer sheets. For optional fragrance, add 5–10 drops of essential oil to each ball before placing it in the dryer. Use two balls for small loads, three for medium loads, and four or more for large loads.