The Ali Express link says "Continuous recording:20hours". But since they offer sizes from 4GB to 32GB it's unclear which storage size that's for. That 20 hours could also be how long the battery will last while recording. But 20 hours is still enough to last the day and then some.
It's probably the battery life. 128 kb/s AAC is effectively transparent even for music, and only translates to 1.1GB. Even if it's uncompressed (1 channel 16 bit 44100hz PCM), 20 hours only translates to 6.35 GB.
