This fish finder can detect and display the grasses, sands, and rocks on the seabed. It uses sonar technology to locate fish or school of fish on any particular area or other solid objects beneath the water's surface and when sonar wave hits a solid mass it will echo back to the transducer. Features: Measure water depth and identify structure where fish lurk Get the approximate location of school of fish or solitary fish With battery safe mode and low battery indicator Big and clear LCD display With Green LED backlight 5 different selectable sensitivity settings With fish depth scale and audible fish alarm Removable transducer float Water-resistant design Anti-UV LCD Specifications: Measure Units: Meter / Feet Display: TN/Anti-UV LCD display Backlight: green LED backlight 4.6cm or 46mm diameter Round transducer sensor Depth Range Max: 100m (328.08ft) Min: 0.7m (2.30 ft) Sensor Beam Angle: 45 degrees Display the nature or circumstance of bottom of Sea (i.e. grass, rock and sand) Operating Temperature: -20°C to 70°CC (-4°CF to 158°CF) Power Source: 4 x AAA batteries (not included) Set Includes: 1 x Fish Finder 1 x Round Sonar Sensor with 7.5m Cable 1 x Bolt 1 x Wing Nut 1 x Neck Strap 1 x English Instruction booklet