Function Well understand the water depth and fish location by the portable fish finder. The fish finder portable gives you alerts when fish and fish schools passing by. 5 modes sensitivity options enable you to use the kayak fish finder in different fishing environments. The kayak fish finder can be used in different ways, such as on ice, fixed to kayak, put it into a hole or float it on water surface. You can understand the composition of the bottom contour. Sands, rocks and weeks will be shown on the LCD display. 3 Specification 2inch TN/ANTI-UV LCD Display. Blue LED Back lighting . Measurement Unit: FT/M 1.81inch diameter transducer sensor.v Detect Depth Range: 3ft~328.08ft (0.6m~100m) under sensor. Sensor coverage range: 45 degrees beam angle in 200Khz. Sensor Operating Temperature: -14°F to 122°F(-10°C-50°C) . Cable Length: 25ft (7.62m) Powered by: 4 x AAA batteries (not included) For Kayak Fishing Attach the Side-Scan Adapter to the boat hull using the mounting tabs. Break though the hull of a boat. Place the fishing sonar sensor against the hull bottom 1 inch underwater. The moving speed of kayak should be below 5mph. For Ice Fishingv You should clear the snow on the ice layer. Make sure the surface is smooth enough. Put the fish finder portable directly on ice layer to detect fish distribution in purpose of selecting a place to drill a hole. There should be no air between the sensor and the ice and no air between ice layer and the underwater either. Otherwise, the portable fish finder will not work properly. Cut a hole through the ice and put the fishing sonar sensor directly in the water. Enjoy the fishing gear