I paired up a Federal Firebeam that I got on eBay (red) with one from a member here (blue) and put them in the back window of my Mustang. Don't you love when they are perfectly out of sync? I mean every say 5 - 10 flashes you go from a cycle of flashing at the same time, to evenly spaced apart, and back to simultaneous. This poll does not have to be only for vintage rotators. You can chime in on your LED preference too.