Assuming this is for in-home...
If you want to use the BNC on back, you will need a right-angle adapter for a back-of-set antenna. Otherwise it will stick straight out from the back which is basically impractical and not "optimal use".
You can, or should be able to, purchase the replacement telescopic screw-in type at the shack as well, and is a cheaper but not very useful option, depending on what you're listening to or how close you are to your intended "target area".
Also, you can use a mobile antenna (which will/should have an attached cable) that will connect directly to the back without the need for an adapter.
It all depends on how much you want to spend, where the unit is being used and how much signal you need to pull in.