Gore-Tex, HyVent, eVent, and any other synthetic fiber garment with a durable water repellent (DWR) or polyurethane (PU) coating will eventually allow moisture to seep through the outer fabric. The Nikwax TX Direct Spray-On is a quick and easy way to replenish that waterproof barrier before your next outing. Simply spray on, wipe off any excess, and allow to dry to reinstate that barrier.