Original Federal Signal Twin Sonic Model 11 beacon lights off a visibar.  This is the motorized master and the slave light that is driven by the included chain.  The motor works well, both lights spin freely and 3 light up, the red light on the slave side will not light up  The domes have scratches, breaks and marks. The chrome skirt also has marks and some scratches. Please check out the 12 pictures that will better show you their condition. This is an old vintage decommissioned light set being sold as-is, enjoy and thank you for looking. I also have a couple TwinSonic 12's listed.