These covers are proudly sewn in our Chicago factory! The cover completely encases the topper, adding an extra layer of protection. The knit cotton fabric top provides a soft and luxurious feel. The cover is made with two separate pieces of fabric. The top piece covers the top and sides and is made of 100% organic cotton knit fabric. The bottom is made with a sturdy 100% organic cotton twill fabric. These two pieces zip together around the bottom edge of the cover. The cover is now machine washable. Please note that this listing is only for the mattress topper cover. It is just a fabric case and does not contain any foam or mattress topper. These covers may work with other mattress toppers but are made specifically for Sleep On Latex mattress toppers.