Very easy to use, seems to work perfectly. I would have liked a little more power, but it's just fine. Stores to extinction light power used before it and that we find the next power. For the rest, exactly meets the specifications. The warranty restriction clauses quite stupid make him lose 2 stars! Some sellers or manufacturers really are taking their customers for fools. 12 months guarantee 12 months and it is not a day less, even if I move to another country after 3 months! The warranty covers the lamp only, not his power pack! You bought and paid for but if you resell, the new owner can not benefit from the guarantee! Crappy ...