SanDisk Extreme 64GB microSD
Recommended 64GB card.
We typically recommend 128GB cards if you want to record in WAV uncompressed audio. 64GB of storage is plenty to record for longer than the battery will run with WavPack Lossless compression. No audio quality is lost with Lossless compression.
Memory card size is a tradeoff between cost, runtime and capacity. Uncompressed WAV data takes 3.9GB per 24 hours of audio at 24k. WavPack lossless can reduce that to 800-2000MB per 24 hours. Typically this will be at the lower end in real field audio with low configured Gain.