Edit 21/01/2014: 460ii yn this flash works well on my 550D, it must be on the M mode and turn it on before turning on the reflex that it recognizes it (thank you to the people having left a comment). The swivel head is well worth the time and respectable recycling. Conclusion after a few months of use, excellent in environment where flash light varies little because you have to grope for the right couple to get flash intensity, reflex setting for the desired exposure.