I have researched long. Because of the good reviews I decided for the YN-565 EX II. At first I had tried the lightning unleashed and was thrilled. However mounted on the camera does not have the flash fires. After further Internet research, I then read somewhere that the flash for the EOS 400D is not suitable. - Too bad. So the flash went back again and looking for a good lightning continued ... Pity is that only an English manual is enclosed.