Nikwax(R) Down Proof(TM) Wash-In is ideal for all down insulated fabrics and clothing. Reduces the water-absorbency of the outer fabric, optimizing breathability. Quick and easy wash-in application. Lasts several washings, non-flammable and environmentally safe.To maintain waterproofing always wash with Nikwax(R) Down Wash. Do not use detergents. Features: Wash-in waterproofing for down-filled clothing & gear Adds water-repellency Maintains insulation and breathability Great for waterproofing down-filled sleeping bags, clothing and comforters 10 fl. oz (300ml) *3-4 season old down sleeping bags should be professionally cleaned or waterproofed.