See what is in the water at a glance: the fish finder shows water depth, approximate fish location for all kinds of fish, and fish size (small/medium/big). It also identifies bottom features such as weeds (short and tall), sand, and rocks. This helps you choose productive spots whether you are fishing from a dock, from shore, or while ice fishing. Broad applicability and simple operation: suitable for fishing from a dock, off the shore, or ice fishing. You can use the fish finder while moving at speeds below 5 mph, provided the bottom of the transducer remains horizontal. Ultra portable and easy to carry: very portable so you can take it anywhere. It includes a neck strap that lets you wear it around your neck when your hands are busy, and it can be easily stored in your tackle box. The unit is powered by 4 AAA batteries and lasts 4–5 hours with fresh batteries in continuous use. It can be used in freshwater as well as saltwater. Accurate depth reading with sonar: the fish finder uses sonar to detect water depth and fish location. Sonar frequency is 200 kHz. The detectable beam angle under the transducer is 45 degrees. The detectable depth range is from 3 ft (1 m) to 328 ft (100 m) below the transducer. Use scenarios Dockside or shore fishing near structure: use depth readings and bottom features to locate weed lines, sand, and rocks and target productive zones where fish are likely to be holding. Ice fishing: wear the unit around your neck as you drill and move; use the depth and fish location information to identify productive depths and align your line with fish activity. Small boat or moving along the water: scan ahead while cruising at low speed (under 5 mph) to map depth changes and locate fish as you move, keeping the transducer horizontal for results.