OurSure RFID Protection, Radiation Shield Magic Wipe, Handkerchiefs 8900101 100% Silver-Nylon Blend Wipe made with silver-nylon blend fabric, very conductive, offers RF radiation shielding effectiveness up to 60 dB for frequencies from 10 MHz to 3 GHz. Protect your body from RF radiation penetration by laying the wipe between your body and the wireless devices such as smart phone, GPS, iPad, microwave oven. Wrap your smart phone to block the phone signal RFID protection for your credit cards. You can wrap the cards with RF tags with magic wipe and prevent hacker from accessing your personal data in your credit cards Size: 12 x 12 inch (30 cm x 30 cm) Hand wash, air dry, do not bleach, do not dry clean