RF Microwave Absorbing Sheet is used to absorb microwaves. It has a plastic coating on both sides for easy handling. Non-woven, nearly pure carbon fiber is used in it to achieve both good microwave shielding and high absorption. The carbon material is conductive in some forms and it is a very good microwave absorber. Make double or triple layers of the Microwave Absorbing Sheet to enhance its effects. To get a high performance, you can combine a layer of high performance fabric shield such as Nickel Copper Ripstop with the Microwave Absorbing Sheet. It is not essential to make grounding for this material.