time. TTL Flash with High Guide Number: GN58@ISO100, 105mm, supports TTL, M, MULTI flash mode; equipped with AF assist lamp for helping you achieve fast focus in dark environment. Supports Firmware Upgrade: equipped with the USB interface, you can download the latest firmware from official website to upgrade the speedlite. Other users-friendly functions: Sound Prompt System; supports real-time display of battery remaining capacity; automatic settings saving; Large-size LCD display and standard 2.5mm PC interface. Specifications: Circuit design: Insulated Gate Bipolar Transistor (IGBT) Guide No.: 58 (ISO 100, 105mm) Flash mode: TTL, M, Multi Trigger mode: Set-top, 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), 22 levels of fine tuning in total External interface: hot shoe, PC port, USB port, external charging port External Power Supply: can be connected to SF-18C or SF-17C charging pack Wireless triggering distance: 20~25m indoors, 10~15m outdoors Additional features: Rear-curtain sync, FEC, FEB, exposure lock, modeling light, power saving mode, over heat protection. Item Size: 6 * 7.8 * 19cm/ 2.4 * 3.1 * 7.5in(Extended state) Item weight: 370g / 13.1oz Package size: 21.5 * 9.5 * 8cm / 8.5 * 3.7 * 3.1in Package weight: 550g / 19.4oz Package list: 1 * Speedlite 1 * Mini Stand 1 * Protecting Bag 1 * User Manual(English & Chinese)