JUST INSTALLED MY NEW VIPER ON A TRI-MAGNET MOUNT ON MY VAN.....IT PERFORMS BETTER THAN THE TRAM 3500 I REPLACED .....THR RECEIVE IS THE BEST EVER....AND SINCE I LIVE HERE IN CHICAGO (AMP-POWER ALLEY). THE ABILITY TO HEAR DISTANCE IS VERY IMPORTANT......SWR'S WERE 1;1 OUT THE BOX, GREAT ANTENNA GREAT PRICE....73's......HOLLOWPOINT