Features: Wireless Transmitter-receiver, Supports 2.4G Radio Triggering and Optical Triggering: --YN320EX is compatible with YONGNUO RF602/RF603 radio triggering signal and Sony optical transmission wireless triggering signal, and it can be used as a master unit or slave unit. High-speed Sync TTL Speedlite & Ultra-fast Charging Recycle System: --YN320EX supports TTL flash flash and high-speed sync(HSS). The maximum sync speed is up to 1/8000s; the recycling time for full output just takes 2s, high-speed charging recycling experience for you. Can Realize 6-group Flash Control Easily: --As a radio master unit, YN320EX supports controlling 6 separate groups. It can remotely control the flash mode, flash output, focal length, number of stroboscopic and stroboscopic frequency of YN560Li/Yn720/YN685/YN560III/YN560IV/YN660/YN860Li. Sound Prompt System & Flash Head Electric Zoom: --When the sound prompt system is enabled, the flash emits different sounds to indicate different working status; with ZOOM button, the flash head can circularly move in the coverage rang of 24mm-105mm. USB Firmware Upgrade: --YN320EX is equipped with USB port. The latest firmware can be download from the YONGNUO official website. Upgrade the firmware of YN320EX to keep it in best performance. Specification: Guide No.: 31(ISO 100,105mm) Flash Model: TTL, M, Multi Trigger Mode: On-Camera, 2.4G Radio Trigger, Wireless Optical Trigger Zoom Range: 24, 50, 70, 105mm Vertical Rotation Angle: -7 to 90 degrees Horizontal Rotation Angle: 0-270 degrees Power Supply: 2 * AA alkaline battery or AA Ni-MH battery(not included) Flash Times: Approx. 220 times Recycle Time: Approx. 2 seconds(with AA Ni-MH battery) Color Temperature: about 5600K Flash Time: 1/350s to 1/20000s Flash Control: 8 level of output control(1/128-1/1), 22 levels of fine tuning in total External Interface: Hot Shoe, Micro USB Port Transmission Distance: 20-25m indoors, 10-15m outdoors for photo sensitive, up to 100m for radio triggering Additional Functions: Lamp head electric zoom, sound prompt, power saving mode, overheating protection, auto-save settings Item Size: 4 * 6.5 * 15.4cm/ 1.6 * 2.6 * 6.1in Item Weight: 225g/ 7.9oz Package Size: 19.5 * 9.5 * 8.5cm/ 7.7 * 3.7 * 3.3in Package Weight: 400g/ 14.1oz Note: In Multi Mode/ radio flash shooting mode/ S1/S2 wireless flash mode, HSS is not supported. Package List: 1 * Flash 1 * Protection Bag 1 * Mini Stand 1 * User Manual(English & Chinese)