Digital Wireless Watch-type Fish Finder depth range max 135 feets with LED back Light. FF518 Digital wireless watch-type fish finder This watch type fish finder is a combo unit that allows you to choose either Wireless fish finder user mode or Clock user mode Depth Range Max/Min: 135Feet(45meters)/2Feet(0.7meters) Wireless sensor: 90-degree beam angle Can be used in ocean, river or lake and is fantastic for detecting fish or schools of fish in any particular area.