That's one tiny microphone! At about the size of a mature aphid, this wired Electret Microphone is perfect for your FONA.
This microphone's very similar to our PCB-mount Elecret Microphone but is significantly smaller and has pre-attached 65mm long wires. We don't have a specific datasheet for it but it can be biased with 2V and 2K impedence. You do need an electret microphone amplifier to boost the millivolt-signal up to line level. The FONA has this amplifier part built into it but something like an Arduino does not.