The Magnic lights, at least the rear, will flash. I've used the rear for a few years now, but I have bad luck with them. They protrude from the bike and get knocked. This is just a natural result of where they need to be placed. They work great otherwise and I can't feel it at all. For a rear it is plenty bright, I don't know about the front. I use a dynamo hub and a B & M light in the front.