Pre-wired Electret Microphone 4 x 1.5mm - 5 Pack
If you need a tiny, tiny elecret microphone then check out these Pre-wired Electret Microphones from PMD Way. The microphone unit itself measures 4mm in diameter and 1.5mm thick, and are (thankfully) prewired 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.