Amazon.com: Mulberry Silk Bonnet for Sleeping with Ribbon 。Highly sought after authentic Mulberry Charmeuse Silk Bonnet is perfect for maintaining healthy hair while you sleep and lounge. Mulberry Silk is the highest quality of silk there is. It’s natural fiber helps your hair to breathe, locks in moisture, prevents breakage/frizz/static and is hyper-allergenic. The healthy Hair Bonnet is: ? percent Mulberry Silk Double layered for extra protection Reversible (Gold/Black) Drawstring Adjustable Silk wrapped elastic for edge protection 21in 19mm