Stretchy silver coated sheer nylon weave. Will shield low intensity radiofrequency and microwaves (with a shielding effectiveness of >50 dB from 30 MHz – 3 GHz), and is an excellent E-field shield when grounded. Create your own designs. Many uses! Sandwich it between your bed sheets, cover your microwave oven, computer monitor, stereo, light cords, circuit box, vacuum cleaner, make a hat, lampshade, window drapes.