If you're looking to give your CB the ability to use it's built-in PA functionality this speaker is the easiest way to do just that. This PA speaker comes with everything you need if you already have the CB.
If you have a PA compatible CB radio, take a look at the back of the radio. You should see two speaker jacks, the one marked PA is where you will plug this speaker into, after that simply flip the CB/PA switch on the front of your radio and you'll have your very own public address system!
We are commonly asked just what public address speakers are used for; when it comes to your CB using an external PA speaker will allow you to:
Listen to your CB outside of your vehicle
Allow you to broadcast your voice through the horn
This becomes very useful in environments where you need to listen to your CB while not inside of it, or in similar situations (like workplace) where you need your voice projected over a wide area, much like a bullhorn or megaphone.