The CR-134 was a mobile, battery-pwered stereo cassette recorder/player from the mid-70's. The main use was for portable high-quality recording similar to the Nakamichi 350/550 or Marantz PMD's except it was even smaller. The CR-134 was not that much bigger than a car audio head-unit. They did get used in cars too. The ultimate set-up for your BMW 2002tii in '75 would have been this deck and an ADS 2001 bi-amplified portable speaker system. You would have had ~$1000+ into the gear and quite possibly were in the music industry to justify the cost. I'd love to find a CR-134 to go with my 2001 system but not that many came into the US. The ones that did are either basket cases now or priced safely out of my reach.