Matsushita / Panasonic CE-501 Omni + Ribbon microphone
Matsushita / Panasonic CE-501
This is a similar concept to the STC 4033A and Western / Altec 639 microphones, with both a ribbon element and dynamic capsule inside.
Originally the two elements combined to give a fixed cardioid pattern, but I have wired the outputs from the two transducers separately to a breakout box to give the choice of polar pattern. You can even send both ribbon and dynamic to separate channels for stereo recording.