identification

Please help! Hi everyone! I just bought the Jeep about 2 and a half weeks ago, after thinking about one for years. I absolutely love it, it only has 73k miles, no body rust, and an unreal solid frame for the north east (which I just POR15'd after lots of thread reading!)... However, it needs...

So I have this antenna stub on the rear of my jeep from the previous owner. I'm wanting to install a CB radio in my jeep and I would like to use an existing antenna mount. Can anyone identify what type of antenna this mount is for? I brought it to an audio big box store but they were no help...