Leaded Electret Microphone 4 x 1.5mm - 10 Pack
If you need a tiny, tiny elecret microphone then check out these leaded electret microphones from PMD Way. The microphone unit itself measures 4mm in diameter and 1.5mm thick, and are (thankfully) fitted with a short wire from each terminal for convenience.
You will need an amplifier circuit in your design to use this microphone. We don't have a specific datasheet for it but it can be biased with 2V and 2K impedence.