Jerry, I purchased the 20 XX. The installation was quire simple and straight forword. The techical staff when questioned were easy to get to and answered all my questions. I could have bought the 10 XX for the same price. They both have the same screen. The 20 is a 4KW unit with a closed aray and the 10 is a 2KW unit with an open aray. The open aray provides a better definition of the targets while more power allows you to see better in fog. This my first Radar unit, although I have used several units on friends boats and charters. I found the target definition very good and the unit easy to operate. I took a one night Radar class from USPS. The fellow giving the class has a 10 X and was very pleased with his unit. He had no problem seeing through the fog. Mark Stypinski M/V Elsea 1974 30 Willard Vega Voyager http://www.geocities.com/Yosemite/Rapids/7196/ W (517) 335-3931 H (517) 333-5915 _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com