for lots of part-15 info
A radio that is compliant with the FCC’s Part 15 rules. Broadcasting on FM spectrum at any power without license from the FCC is illegal. However, open-air broadcasting at microscopic power levels below 1/25th of a watt, or 25 milliwatts without a license is allowed. 25 milliwatts is only enough power to transmit approximately 100 feet, but this transmission distance is variable depending on obstructions, antenna, and other conditions. The radios used in the Radio Re-Volt have the power of .001 watt.
