Firestick makes bot GP and NGP antennas... (NOTE an NGP will work with or without) I'd make sure it's an NGP.
NOTE: Most better truck stops carry them, you can walk out today.
Mine (phictured in another thread) is a competitor's NGP, works well, I'm sure the firestick NGP (I think they make two of those, one longer) The longer one shoudl work as well or better than mine.
Of course I don't use CB that much..... I push 100 watts into 50 feet of wire (or more depending on where I'm parked) on 80 or 40 meters Ham Bands.. Way nicer.
But I use CB on the freeway.