Power microphones.

Power microphones.
Power microphone have a built in amplifier to make your voice louder.
There are many different types and they may range in price from less than £10, although some may cost more than some CBs do. You should be aware that some of the really cheap ones may make you sound worse than you did before, and may just cause you to interfere with other channels without any great improvement.
Some power microphones will use better quality elements inside, some may also shape the sound to be clear, which is better than just boosting the sound.
Another point to note is that if you use one in a vehicle, any noise in the vehicle will also get louder. In a noisy environment, you may gain nothing as the noise may cause problems for people trying to hear you.
For noisy situations, there are special noise cancelling microphones (see below).

If you do use a power microphone, remember to be careful not to turn it up too far. There is a limit to how much sound you can put onto FM CB before you will just sound terrible and cause interference.

Noise canceling 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.

Base station microphone.
These are designed specially to be used on a base set up, rather than in a vehicle.

Microphones of this type usually include a way of locking the transmit switch on, to release your hands for other things. With the way these often pick up sounds, you can usually move about while talking and still be heard.
As these are power microphones, they will have a volume control on them and some may also have a tone control.
Some may also have a built in echo with a control on the top to adjust the echo level.
The price of these may vary, with some being quite expensive. However, there are some that really do sound good and are worth the money to an enthusiast.