A quality micro-espion is characterized by several criteria, such as:

1. Audio quality: the micro-espion must clearly record the sounds, without background noise or distortion.

2. The range of transmission: the micro-speople must be able to transmit the recordings to an external device over a reasonable distance.

3. The duration of registration: the micro-espion must be able to record for a sufficient time to cover the desired period.

4. Reliability: The micro-spying must be reliable and not fail at the crucial time.

5. Discretion: The micro-espion must be discreet and not attract attention.

6. The ease of use: the micro-espion must be easy to use and configure.

It is important to research and read product reviews to find a quality micro-espion that meets your needs. It is also important to comply with local privacy and surveillance laws when using a micro-spion.