Removable bamboo fabric duvet cover for Polar Night weighted blankets is made of 100% Natural Bamboo Viscose to keep you cozy and comfortable while you rest. The bamboo is one of the most breathable and softest fabric. Specifically designed to fasten in eight places to the Polar Night weighted blanket insert (sold separately) to ensure your blanket won’t slide around within the cover. Zipper closure makes the machine washable duvet cover easy to remove and replace for spot cleaning. Protect your weighted blanket to extend its life and change the look of your plain blanket to match your decor.