Sony TC-158SD tape recorder
I don't have a great deal of information just yet as this unit has yet to be repaired or properly researched by me - enjoy the images in the mean time! The TC-158SD is a high end portable stereo cassette tape recorder, likely designed for professional or semi-professional use (ie journalism, field recording, universities, etc), that was also sold in Japan as the TC-3000. It runs on a fair number of D cell batteries, and features dolby noise reduction and separate EQ/bias selectors for types 1, 2 and 3 cassettes. It's actually a very bulky machine, larger than my Panasonic RS-269US (a home, non-portable deck). As you can see, my example is sadly missing the lugs on the side for a shoulder strap to attach, and is fairly corroded, though nothing seems to be broken or irreparable.