Power microphones.

This is a special type of microphone, designed for use in noisy environments such as in a noisy vehicle.
The microphone has a built in amplifier and is designed to amplify sounds which come from close to the microphone, while reducing the level of those from further away.
Unless you are in a noisy place, this type of microphone will not be of use and you may find a microphone that will pick up your voice from further away is more useful.