This Earthing Fitted Pillowcase Grey Color Radiation-proof Kit is made with 100% Cotton and Silver Fiber for better grounding and EMF protection. With a 98k ohm resistor, it matches the same ground potential of the human body for optimal results. Benefits include reduced soreness, improved circulation, stress relief, enhanced recovery, and more. To use, place on pillow and insert one end of the Earthing cord into a properly grounded wall outlet or Earth ground rod. Any bare skin contact will transfer the Earth’s energy to one's body once connected. To clean, wash a minimum of 2x per month/weekly with warm water (105° F) and dry in a dryer on low or line dry, avoiding bleach, fabric softeners, whitening detergents, oxi-detergents, body oils, etc.