Used in the 1950â€™/1960â€™. If youâ€™re over 40 you can remember the last Friday of the month at 10:00 a.m., they would test these. This one was donated to the museum by the city of Beverly Hills. Made by Federal Sign & signal Co. These pictures are from a military vehicle museum the American Society of Military History based in South El Monte, CA. www.tankland.com These pictures are Copyright 2009.