1975 saw the emergence of polymer tantalum electrolytic capacitors with much higher conductivity conductive polymers replacing the manganese dioxide leading to lower ESR. NEC released their ...

We’re talking of course about the air-dielectric variable capacitor, the tuning element for millions of radio receivers back in the day but now long ago replaced by much flimsier polymer ...

The capacitors are manufactured using a base metal ... with 100% tin for robust soldering and are available with polymer terminations to prevent board flexure damage. They are RoHS-compliant ...