Detailed product description Where the fish is? How can I catch more fish? Maybe you have ever been confused by such questions. By using the MUSTi 8850 fishfinder, you could say goodbye to the days of not knowing where the fish is when fishing and then enjoy your fishing life freely 1. Features 1) switchable fish identification mode 2) fish / shallow alarms. 3) high / low sensitivity setting: . 4) on / off / auto back light 5) adjustable display contrast 6) power save: on / off. 7) depth units: meters / feet. 8) celsius / fahrenheit temperature units 9) fresh / salt water environment 10) true changing water bottom graph. 11) preservable program setting 12) storage bag and neck strip 13) big / small fish identification 14) water resistant 15) earphone sonar adapter 16) choose detecting range automatically 2. Brief specifications: 1) unit dimensions: 120mm X 55mm X 23mm. Sealed and waterproof. 2) display: big adjustable high-contrast dot matrix LCD 3) resolution: 130 pixels (vert. ) X 64 pixels (horiz. ) ; 8, 320 total pixels. 4) power requirement: 4 X AAA alkaline batteries 5) battery life: 20 hours continuous use 6) depth range: from 0. 9 to 45 meters (3 to 148 feet) 7) operational temperature: from-10c to 50c (14 fto122 f) 8) sonar sensor frequency: 190 khz 9) sonar beam angle: 45 10) sensor cable length: 10 M (35 feet) 11) back-up memory: built-in memory stores sonar settings when the unit is turned off.