The Comet Independent Series Antennas are ideal for installations where metal surfaces are limited and no options for grounding are available. The GI250 is truly a no ground plane needed and is designed to work for in all Amateur Radio applications such as mobile and portable operations. The GI250 can be installed on RV’s, Boats, Golf Carts, ATV’s, Motorcycles and more! Each model has an option for either NMO or UHF type antenna connectors. The GI250 is only 39″ and provides for 2.15 dBi on VHF (144MHz) and 5.5 dBi on UHF (440). Max power rating for the GI250 is 200watts!