Detect sensitivity: Lucky fish finder transducer controls how many details shown on the display. You can set up the sensitivity from 1 to 10. The more sensitive it is, the more detailed it can detect. Fish alarm: An alarm will sound when the portable fish finder detect fish corresponding to the alarm setting. It can distinguish the relative fish size(large, middle and small) in a certain water area. Units: Four different units from the menu--M/, FT/, M/, FT/. Multi ways to use: Tie the fishing line to the hole of the sonar sensor, and cast it to the water. Attach the adapter to the fishing boat hull using the mounting tabs. Ice fishing, river fishing, sea fishing, kayak fishing, shore fishing. Wireless Sonar Sensor The wireless sonar ball of the wireless fish finder comes with 2 fish attractive lamps. It can help you find the fishes more easily. The detect angle of the sonar transducer is 90, and the detect depth is from 0.7m(2.3ft) to 45m(147ft). The wireless operating distance of the depth sounder can reach to 60m(196ft). Warm tip: please pull the antenna out when you detect fishes in the water. Specification 1)Display:2.4inch TFT color LCD, pixels:240Vx960H 2)Back lighting: On/off White LED 3)Depth Capability:147feet(45m) 4)Sonar Coverage:90 degrees beam angle in 125Khz 5)Power:3.7V rechargeable lithium batteries 6)Waterproof design:level-4(spray-water-proof) 7)Operational Temperature:14F to 122F(-10C to 50C) 8)Built in memory stores sonar setting when the fishfinder is turned off