When choosing a micro spy, it is important to consider the following factors:

1. Transmission range: The range of the transmission determines the maximum distance to which you can listen to the recordings. It is therefore important to choose a model with sufficient scope to cover the area you want to monitor.

2. Audio quality: audio quality is important to capture clear and distinct recordings. It is therefore important to choose a model with sufficient audio quality for your needs.

3. Disclaimer: discretion is important if you want your surveillance device to remain hidden. It is therefore important to choose a small and discreet model that can be easily hidden.

4. Additional features: some additional features, such as noise reduction, can be useful to improve audio quality. It is therefore important to choose a model with additional features that meet your needs.

5. Battery life: the battery life determines the amount of time during which the micro-espion can be used without charging. It is therefore important to choose a model with a battery life sufficient for your needs.

6. Cost: the cost can also be an important factor to consider when choosing a micro-espion. It is therefore important to choose a model that meets your needs while staying in your budget.

Taking these factors into account, you should be able to choose a micro-espion that best suits your needs.