Extra-wide size & waterproof shell fully covers hair & preserves your style Tuck-free! The open-back design makes it easy to keep all loose hair dry Unique adjustable back wire closure delivers a secure & comfortable fit for most hair lengths Luxurious satin lining is gentle on most hair types & keeps hair frizz-free Super-soft inner layer offers extra comfort for a spa-like shower experience OEKO-TEX® Certified: This certifies that our satin is safe, sustainable, and environmentally friendly.