Removable cotton fabric duvet cover for Polar Night weighted blankets is made of 100% premium cotton fabric to keep you cozy and comfortable while you rest. Specifically designed to fasten in 6/8 places to the weighted blanket insert (sold separately) to ensure your blanket won’t slide around within the cover. Compatible with other brand same size weighted blanket. 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 décor.