Canon Speedlite 580EX II Instruction Manual page 57

pecified in the instructions. If such changes or modifications should be ma
you could be required to stop operation of the equipment.
This equipment has been tested and found to comply with the limits for a cla
B digital device, pursuant to part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference in a
frequency energy and, if not installed and used in accordance with the
insbuctions, may cause harmful interference to radio communications.