Designed for salt water or downrigger tracking. Same great features of the X-135 with: 5" diagonal, 480V x 480h pixel film SuperTwist display, white LED backlighting, high power output, "flasher mode", speed and water temperature included. Includes dual frequency 50/200 kHz skimmer transducer (4000 watts peak-to-peak power for depths to 2,500') with built-in temperature sensor (HS-50/200-DX) and speed sensor (SP-X).