Batteries are included - as long as they hold to be seen. An instruction manual is missing - but really a lot to operate does not exist. Only the function of the slider on the back is unclear to me. Did the part tried so far only at room light - experience has shown that there is always something problematic in bright surroundings IR - but that's a general problem of the technology, not the device.
I suspect, as some others, that this is here to the identical part that even Canon sells. Only that the original cost many times over.
Conclusion: For the price absolutely recommendable. A star's deduction for lack of guidance and the long delivery time.