The YN565EX III is equipped with the USB interface, you can download the latest firmware from YONGNUO official website to upgrade the speedlite. External power: YONGNUO external charging, boxes like SF-18C, SF-17C (not included).
Strong, fast, and cheap as compared to the Canon Version. I would buy 4-6 of these and have plenty as spare comparing to buying 1 from Canon. Last Yongnuo flash lasts over 1 years for me after continuous using.