Thanks Dmathieu !
Dmathieu, are you sure that there are FB-FH with halogen bulb ?Federal Signal's 2nd Version Flash Ball was still a non rotating light like the Version 1, with some design changes.
It had the larger magnet, was available in halogen or incandescent bulb, and had a new reflector and socket design.
The reflector was still stationary. The bulb was flashed by a flasher for a directional warning.
These Flash Balls are even more rare than the Version 1 Flash Balls.