trigger modes, automatic settings saving and custom setting supported: --YN568EX III can be triggered by the camera set-top, PC synchronization trigger and wireless optical trigger off the camera. Supports firmware upgrade: --The YN568EX III is equipped with USB interface, you can download the latest firmware from YONGNUO official website to upgrade the speedlite. Equipped with large-size LCD display and 2.5mm PC interface, and supports the battery remaining power real-time display, convenient to use.Specifications: Circuit design: Insulated Gate Bipolar Transistor (IGBT) Guide No.: 58 (ISO 100, 105mm) Flash mode: TTL, M, Multi Trigger mode: On-camera, Sc, Sn, S1, S2 Zoom range: 24, 28, 35, 50, 70, 80, 105mm Vertical rotation angle: -7~90 degrees Horizontal rotation angle: 0~270 degrees Power supply: 4 * AA batteries(not included; Alkaline or NI-MH are usable) Lighting times: 100~1500 times (with AA alkaline battery) Recycle time: Approx. 2s (with new AA alkaline battery) Color temperature: 5600k Flash time: 1/200s~1/20000s Flash control: 8 levels of output control (1/128~1/1), 29 levels of fine tuning in total External interface: hot shoe, PC port, USB port Wireless triggering distance: 20~25m indoors, 10~15m outdoors Additional features: Master flash, High speed sync, Rear-curtain sync, FEC, FEB, FE lock, electric zoom of flash head, sound prompt, auto-save setting, PC sync, USB port, power saving mode, overheating protection, advanced options setting. Item Size: 6.2 * 7.2 * 18.8cm/ 2.4 * 2.8 * 7.4in(Extended state) Item weight: 383g/ 13.5oz Package size: 21.5 * 9.5 * 8cm / 8.5 * 3.7 * 3.1in Package weight: 565g / 1.2lbs Package list: 1 * Speedlite 1 * Mini Stand 1 * Protecting Bag 1 * User Manual(English & Chinese)