?Both of the wireless fish finder and the sonar are rechargeable. Come with a USB cable for charging. The hand held can last 4 hours with full charge and the sonar sensor can last 10 hours with full charge. ?Various features settings: detect sensitivity, screen brightness, depth range, zoom, depth alarm, fish alarm, fish icon, units alter and language choose. ?The wireless fish finder supports 196FT(60m) wireless operating range(There is an antenna on the left top of the hand held, please pull it out), 147FT(45m) depth detection. You can go fishing in different ways with it, such as ice fishing, river fishing, sea fishing, fishing off the shore, kayak fishing or fishing in the night. ?The wireless sonar transducer, with fish attractive lamp, makes it easier to detect fishes. It has a transparent replacement cover, so you can see where the sensor is even in the dark. ?The portable fish finder, with 2.4inch TFT color LCD screen, can detect and display underwater contour, water depth, water temperature and fish size with depth. It has two user modes: WIRELESS/SIMULATION. You can try all functions in simulation mode and go fishing in wireless mode.