MORE PROFESSIONAL：The portable fish finder has an updated 3.1 inch TFT color screen LCD (clearer display). The sonar transducer can be attached to the hull of the kayak or boat to understand the ice/underwater situation. It can detect and display the fish size (big/medium/small) and fish depth, short/large weed, sand/rock, water depth, water temperature. GREATER DETECTION RANGE：This sonar fish finder comes with 25 feet cable and depth detection of 328 feet, it has a detection angle of 90° and detection frequency of 200Khz, can detect the location of fishes activity. The sensitivity can be adjusted in 5 levels. In clear water, we recommend higher sensitivity, so you can see where the fishes are. USEFUL FEATURES：Intelligent fish alarm: you will get alarms when fish or schools of fish pass by; Backlit display: the display is visible even in sunshine or darkness when you turn on the backlight; Sea grass/rock detection alarm: can help you avoid obstacles. Normally, this depth sounder lasts for 4-5 hours (Note: 4* AAA batteries are not included). With power saving mode on, it will work longer. The design of the replaceable battery is not affected by the power of the fish finder. PORTABLE HANDHELD：The fish finder is designed for one-handed operation and comes with a neck cord , it weighs about 0.9 pounds, light and small design is more suitable for kayak fishing and small boat fishing. If you do not go to the lake often or have a smaller fishing boat that can not install a large GPS fish finder, a portable fish finder may be the best choice. APPLICABLE TO VARIOUS WATERS：Compared with the wireless fish finder, the fish finder uses the cable design to transmit signals more stably, is more suitable for complex waters, and can also prevent the loss of the fish finder. It can be used for ice fishing, ponds fishing, river fishing, lake fishing, sea fishing, clear water or muddy water and so on. If you like fishing or your family and friends like to fish, this is a great gift.