Marantz cassette recorder model SD-4000. From 1979 - 1981. features sendust alloy 3 head system, two speed playback standard/high rec mute, tape selectors normal - CrO2 - Fe-Cr - metal, Dolby Nr. on/off, Mpx filter on/off, monitor source/level control, analog counter with reset, monitor source/record level selector, both right/left mic inputs, and phones output for stereo headphones. both right/left VU meters. Neat cassette deck.