Rauland Spectrum Master .... Model 3570 Log-8 Microphone Mixer Expander...(Rauland-Borg)...8 Channel ...They are used to expand mic. sub-channels.....I have two...Easy to rack mount.....will sell the pair for $60..(I have posted this for a few months which is fine....These are unique equipment.)........Call ... for more info...Thanks
Location: Englewood