A very long time ago our PA system was a Shure Vocal Master. This ancient thing had six 1/4" phone jack inputs, and a spring reverb. Two big vertical column speakers. Anyway, the old mics that came with it were in plastic cases like Joey described, and sounds kinda' like the same thing. The model designation long escapes me, but the boxes said Unidyne. It was a funny word to me. They're probably still in those boxes packed away at the old James River Music Hall.