I ditched the GME aerial that came with the unit after a few years.It was a 4db,but I think the aerial was either not fitted to the cable to well,or the cable was not as good internally as it should have been.It was ok for some things,but I would sometimes lose contact with the group I was travelling with over a small hill.I decided to upgrade to a RFI aerial,and chose the CD5000.This has been an excellent choice.I have no problems with communication,and last weekend on the Wonnangatta trip,had communication with all vehicles spread over a 15km range.