Nikwax Soft Shell Proof adds surface water-repellency which reduces water-absorption, minimizes weight gains and maintains insulating properties. An easy-to-use wash-in treatment that helps to maximize performance and extend the life of the fabric's water-repellent finish. Ideal for use on soft shell fabrics such as PolarTec, Windstopper, Windbloc, Schoeller, Driclime, and Apex.