Shields Cell Phone Radiation. Who needs cell phone shielding in a pillowcase? If you know anyone who puts their phone under their pillow (where it can radiate their sleeping brain all night), they really need this shield! Benefits both teenagers and adults alike. Cotton based, machine washable (no bleach!) but with superfine silver fibers (you need a microscope to see them) woven into it. Provides significant signal reduction. Phone function and sound quality are not affected. Finished size is 50x70 cm, for standard pillows. We reccomend that you put a standard pillowcase over this one.so you don´t have to wash as often. Note: we don’t recommend having a cell phone anywhere in the bedroom. But if you must, shield wisely.