These are wool dryer balls purchased last year. They were used once or twice and then stored at home. Since they are a material that easily attracts lint, there is some pilling. Material: 100% wool. Size: Approximately 7.5cm Package contents: 6 dryer balls, Reusable: Dryer balls can be used approximately 1,000 times. They effectively shorten drying time by about 20-30%. Easy operation: Simply put the wool dryer balls directly into the dryer and add a certain amount of dryer balls according to the amount of clothing. After use, take out the wool balls, dry them, and store them.