I wrapped my cell phone up in the hat. and watched for an hour. i was able to receive calls, texts and fb messages while wrapped in the hat.
Please be sure that the Cap you received is from EMR Shielding Solutions, you will find this information written on the label inside the Cap; written EMR Shielding Solutions, and Made in Canada. The Cap significantly reduces the RF signal. A cell phone needs very low signal in order to operate. The best approach is to measure the shielding levels with a meter.
The EMF and RF Protection CAP can be Hand-washed. The EMF shielding material used for the shielding the cap does not contain silver, therefore the effectiveness of the cap will remain the same after the washing.