B&M Seculite Plus tailight - chrome base

B&M Cyo Seculite Plus talilight - the shiny chrome version (the photo shows the black base version).  

This is a dynamo tailight that mounts on a fender.  Really - has to mount on a fender.  Probably too stout for use on plastic fenders.  Very nice quality, but you can add epoxy or silicon to seal it even better.