Nikwax Down Proof is a specialty waterproofer designed to protect the insulating properties of down-filled gear from wet and damp conditions. It maintains warm insulation and minimizes weight gain while prolonging the life of your gear in wet weather. Apply this product to used down or feather-filled clothing and accessories to keep items in perfect water-repellent condition. It is easy to use in the washing machine or by hand, making it ideal for all feather-filled, down clothing and accessories, and recommended for Puffa.