Castable: No more long heavy cable for transducer. Clear Color Screen: it comes with clear color TFT LCD display (2 screen background colors selectable - black and white), which enables you to read the screen in bright sunlight or at night. It applies to lake, river, sea and other fishing environment. Suitable for fishing from a kayak or boat, casting from the shore or using for ice fishing. It detects and displays water depth, water temperature, fish size (small/medium/big), fish depth, and bottom contour. It has Work and Simulation Mode. Measure units of depth and temperature can be converted. Sonar Beam Angle: 90 degree. Depth Range: 2.6-131FT/0.8-40M. Maximum Distance between the sensor and the screen: 262FT/80M. No need to drill hole in your boat hull to install the sensor any more. Two small holes on the sensor allow you to tether with your fishing line and cast it onto water as far as you want. Note: 1. Please change the background from black to white in bright sunlight to get more visible readout. 2. When the sensor is off, its battery Indicator on the display is incorerct. Red indicator light on the sensor will turn off when it is fully charged. If you would like to check the sensor's battery status from the display, please put the sensor in water. It will turn on when it floats on water. The sensor's battery Indicator on the display will then display correctly.