Wool dryer balls shorten drying time, soften and fluff fabric, and can reduce static. They are great for cloth diapers and all laundry! They help bed sheets stay untangled in the dryer. They are all-natural, with no synthetic fibers or chemicals used. While some other brands use center fillers or low-quality wool, Buttons dryer balls are made of 100% New Zealand wool. They will not unravel and will last for years. They may develop some pilling, but pilling makes for softer laundry because a larger surface area improves softness and drying time. Wool dryer balls are quieter and more gentle on clothing than plastic dryer balls with nubs.