You've probably never heard of the Tefifon, but for a short period of time in 1950s and 60s Germany, this music player was like the latest Apple Watch: a little bit silly, a little bit cool. Invented by a German engineer named Karl Daniel, the Tefifon was sold in post-World War II Germany and imported in the US very a brief stint. (It never really took off.)Basically, this musical artifact combines vinyl and 8-track technology—it plays a cartridge full of spooled tape, but they're not magnetic. Instead, the Tefifon plays music by pressing a stylus to etched grooves, just like vinyl. It sort of looks like a scale with a plastic wheel that turns in one direction.You can still find vintage Tefifons on eBay for around €100 ($100)—but for the most part, they're pretty much obsolete. Skip to the six-minute mark in the video to see this nifty thing in motion.