Lucky 40M Wireless Sonar Fish Finder 100% waterproof floating sensor Wireless Range:35 meters (or 115feet) Depth Range:0.6 ~ 40 Meters (2~131 Feet) Can be used on both fresh and salt water such as ocean, river, lake, etc. even on ice or icy water. Find out theLocation of fish,Depth and Bottom Contourof water. With the advanced sonar detection technology