wilson is way better than a k40 and "firesticks" are just as adjustable as wilsons or k40's there are alot of knock off of the firesticks if it doesnt say firestick dont get it, there adjustments are under the rubber cap on top. wilsons antennas have a stronger magnet than k40's and also handle way more power. i run a wilson 1000, mag mount and it hardly ever gets knocked off the k40s have a weak mag and are alway a problem. what ever antenna you get SWR it in. look at radio active radios website they sell only quality stuff there. or find a redmonkey (they are in california)location.