Package Include: 4 Resuable Dryer balls come in set and are designed to go into your dryer with your wet laundry. Air Pockets: As they tumble around with your clothes and linens, they create pockets of air between the items and layers of fabric, which aids in the drying process. These air pockets allow for improved airflow throughout the dryer, which can help your laundry dry up to 25% faster than it would without dryer balls! Fewer Wrinkles: Dryer balls are also helpful for preventing wrinkles from settling into fabrics, particularly when drying smaller loads. Dryer balls help separate the items as they tumble around, making it much less likely that anything will get trapped against the sides of the dryer drum for any length of time. And more movement within the dryer means less time for wrinkles to develop.