White Replacement boards for double sided reader board frame. Special markers used on these boards, will not wash off with water rather with glass cleaner and a soft cloth or paper towel. Only use with the Re-Markerable markers. Not for use with washable or white board markers. Measures 24" x 36" and can fit in other sandwich boards or menu boards that accomodate that size. For indoor use only, however many of our customers use these outdoors as well.