there is only an amp if you have the factory sub. the speakers are not amped. You'll need the three parts below for the install (dash kit, harness, antenna adapter).
If you do have the factory sub then you will also need to get a male rca end to hook it up. there is a third plug that has the signal and turn-on wires in it that you connect to. there isn't an adapter made for it so it has to be spliced in to the factory harness.