[. . . ] Also be sure to follow all warnings and instructions marked on the product. [. . . ] Use only the type of power source indicated on the printer's label. Operation is subject to the following two conditions: (1) this device may cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio or television reception. However, there is no guarantee that interference will not occur in a particular installation. [. . . ] Changes or modifications not expressly approved by the manufacturer could void the user's authority to operate the equipment. [. . . ]