Specifications: Measure Units: Meters / Feet Display: LCD Backlighting: LED sensor 4.6cm diameter Round transducer sensor Depth Range : maximum: 100m (328ft) ; Minimum: 0.9m (3ft) Sensor Beam Angle: 45 degrees Display Display the nature or circumstance of bottom of Sea (i.e. grass, rock and sand) Temperature Operating Temperature is from -10°C to 45°C (14°F to 113°F) Battery Battery: Uses 4*AAA batteries (Not included) 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 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 0 degrees during .6. Strong waves, suspended matter and muddy water,will affect the performance. How to use the Sonar Sensor:1. Toss the sensor and 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.