Already when unpacking I was a bit skeptical because the lamp glass front is exposed around the full circumference and consists of a hard, easily breakable plastic. A few weeks ago my lamp has now been dropped from height and the hand so that the glass is broken. A call to the service of BuM brought clarity - the glass is not to apply as a spare part, a repair will cost 35 euros.
For the money, I would rather buy myself a more robust lamp. To build a bike light so that it does not survive a single case from 1m height I think is completely vorbeidesigned and would have expected at least some goodwill in this service.