An antenna, and a power supply. If you ran it in a car you'd run it off the battery instead.
I should have mentioned, it's been widebanded and capable of Rx and Tx from 138-172Mhz, where the user has a licence that permits them to operate outside of the 2zm ham band (I used to use it on the UKSAR VHF freqs). It includes a car mount3 (which has been drilled) and the original DTMF mic in A1 condition.
Very high quality heavy duty unit, but I've got more V and U gear than I can shake a stick at so I'm rationalizing the collection a bit.