Wool dryer balls. They are a natural non toxic alternative to dryer sheets. I haven't used dryer sheets in over a year. Yep mine have lasted that long. They cut your dryer time from anywhere to 25 to 75% depending on what your drying and how big the load is. They come in sets of 4 or six. You can add a few drops of essential oils for scent. They also prevent static cling.