tested with the YN TX 622c and a flash gun 420EX and YN 568II. The manual is in English or Chinese. But the figure of ModOp seem light up For. English is also understandable. Initiates high speed e-ttl. Also allows the setting from the control YN622C TX smoothly. Operation is relatively simple. I am happy with my purchase. The downside is the size of the box. Similarly fixing the flash is not facille, there is little room to screw the knob.