Mattress protector mattresses protect your mattress from sweat and small amounts of liquids. they are not completely liquid proof. for liquid-proof and membrane-coated products, you can type elymkrkapfit00 for microfiber product or ystk79 for cotton product in the search bar. top surface: 100% microfiber fabric. investigate the advantages of microfiber fabric. bottom surface: interlining. photos are available. (it is a lining derivative fabric.) side surface: the side surfaces of your bed are completely closed thanks to the combed rubber sheet. it provides protection against the formation of dust mites and other allergens. it is ideal for people who have night sweating problems. it is useful for long-term inpatients. for the right result, you should measure your mattress and choose the size according to its exact dimensions. if your bed is 160x200, you should choose 160x200. do not choose neither large nor small. Improved version for clearer understanding and better search visibility. Suitable for users seeking detailed and reliable product information.