1.The wifi cover is made by Copper/ Nickel/Polyester Fiber which is certified to provide 99.999% protecting. This fabric has good conductivity and shielding effect. The wifi cover is designed by two sides open, you could choose different level blocking strength by opening the side or closing the side. The closer, the blocking performance will be better. You could tie up the two open sides to let it closed. It is very easy to use, cover the router entirely, especially cover the router antenna. Then it can play its function. 2.WiFi routers are now ubiquitous in homes, offices, hotels...... All over the place. We have been suffering from these electromagnetic troubles and unknowingly threatening our 3.The wifi router cover which can be used for most WIFI routers with or without antennas. In addition, it is very lightweight and easy to use, so you can take it with you and use it for any occasion. 4.Our EMf blocking WIFI Cover is made of breathable emf protection fabric that allows a natural air flow for cooling. Just tuck around the entire modem/router for the greatest performance. while it may affect wifi signal if wrapping the entire router, we suggest only wrapping the router antennas when you use wifi. And wrap the entire router when you are sleeping or outside. Please note, the cover is not advised to wash.