Nikwax TX. Direct Wash In Waterproof Waterproofing, 99 ml

Restores water-repellency and revives breathability of all waterproof garments
For use on all waterproof outerwear, such as rain and ski jackets, and synthetic sleeping bags
Easy wash-in application; machine wash safe
Recommended for technical clothing, synthetic sleeping bags, rain and ski jackets, GORE-TEX, Patagonia, North face, Columbia, and arc'teryx
Water based, biodegradable, and contains no PFCs, VOCs, optical brighteners, or added scent