Ok - it is 405nm. Hang on - I'll upload a photo. I am sure sanwu will figure it out but I am curious - I am not super knowledgeable but I read somewhere about diodes sometimes "switching modes" or something like that.
I have a sanwu 800 mw challenger - have had it for a few weeks. Looked great at first but the beam recently weakened (at all mode settings) and there are two strange artifacts. First, the "dot" is no longer a dot. It is like a dot surrounded by two crescents - there are three separate "lobes"...