OurSure is only an authorized seller for OurSure Brand products. The quality and efficacy of OurSure products is our priority. The only way to ensure you are buying authentic products is to purchase them through OurSure store at Amazon. This Tank top is specially designed for shielding Radio Frequency (RF) radiation such as mobile phone, wireless devices, microwave oven. The high-tech conductive textiles are Lightweight, breathable, comfortable, and safe on skin. The fabrics undergo rigorous testing and have up to 60 dB shielding effectiveness in frequency range from 10 MHz to 3 GHz.