This is a tie-clip style external microphone for tape recorders. It costs 4000 yen (excluding tax). The fourth photo shows an example of a TCM-400, and it is compatible with models that have "plug-in power" written on the microphone terminal. Most tape recorders are compatible. It offers higher sensitivity and better sound quality than the built-in microphone of the tape recorder itself. Perfect for recording at a distance from the tape recorder.