Features: Sensitive: The sensitivity can be adjusted freely according to the depth of water. Detect and display water depth, approximate fish location, fish size, short & tall weeds, sand & rocks on seabed. Setting can be saved when turned off. Apply to lake, river, sea and other fishing environment. Depth range from 1M to 100m. NOTE: The depth is measured from the sonar sensor, not the float. Round transducer with cable and removable transducer float. Can be used for fishing off the dock, on a boat, and ice fishing. Various features settings: 5 user selectable sensitivity; battery save mode; backlight mode; fish alarm; unit of measure. Water depth shows by meters/feet. Specifications: Condition:100% New Color: As shown in the picture Measure Units: Meters / Feet Display: LCD Backlighting: LED 4.6cm diameter Round transducer sensor Depth Range : maximum: 100m (328ft) ; Minimum: 0.9m (3ft) Sensor Beam Angle: 45 degrees Display the nature or circumstance of bottom of Sea (i.e. grass, rock and sand) Operating Temperature is from -10C to 45C (14F to 113F) Battery: Uses 4*AAA batteries (Not included) How to use the Sonar Sensor: 1. Toss the sensor and float into the water; 2. Attach the Side-Scan Adapter to the boat hull using the mounting tabs; 3. Attach the sensor to a handle, lower the sensor into the water. Package List: 1*Fish Finder 1*Instruction Manual 1*Lanyard 1*Fixing Screw 1*Fixing Frame 1*Sensor Note: 1. It will turn off automatically if the depth display reads "---" continuously for 5 minutes. 2. The transmitter is waterproof, but the receiver (unit with screen) is not waterproof, so please do not submerge or spray the fish finder screen with water. 3. It can not be used to detect bait fish(motionless) or fish that is smaller than 10cm. 4. When use this fish finder on moving boat, please make sure the moving speed is slowly (lower than 5 mph). 5. Extremely cold weather will impact the performance of the product. It is suggested that you keep the unit in temperatures above 0 degrees during operation. 6. Strong waves, suspended matter and muddy water,will affect the performance.