What it displays: Water depth, water temperature, relative fish size (small/medium/big), fish depth, and water bottom contour. Sensitivity Adjustment: There are 20 levels of sensitivity setting. Targeting fish in deep/dirty water generally requires higher sensitivity, while shallow/clear water requires lower sensitivity. Clear Color Screen: It comes with clear color LCD display (2 screen background colors selectable - black and white), which enables you to read the screen in bright sunlight or at night. Fish alarm: An alarm sounds when a group of fish is detected. The alarm feature can be turn off if you prefer quiet fishing. Rechargeable: Both the handhold units and the sonar sensor are rechargeable.