The 19 dx iv delivers full 4w power and features like rf gain control, instant channel 9 and 19, pa system, and an illuminated display in a compact, recreational design. Features rf gain: adjusts receiver sensitivity to match incoming signal compact design: installs easily into most cars and trucks illuminated lcd display: for bright, clear visibility of display electronic tuning: allows precise tuning of all 40 channels instant channel 9/19: immediate access to emergency channel 9 or information channel 19