Another must have !You don't need cell phone coverage to use it ! It will work anywhere in the world.It creates its own WiFi hotspot and you can share its signal with as many people as you wish or password protect it just for yourself.This is a ultra portable WiFi transmitter .uses a free app.It has a self contained battery and can be pulled behind your boat, cast or thrown from shore.Depth Sounder Features: - AutomaticRanging, Sensitivity - Transmit Range: 100 yards -Water Temperature, Depth Indicator - Audible Alarmsfor Fish/ Shallow/Low Battery - Fish Icon - ZoomBottom Track - Noise Rejection - Surface Clarity -Battery Indicator - Screen controls: Touch screen,split screen display with touch screen zoom control.Specifications: - For Casting or Trolling - Transducer:Water activated transmitter - Max depth range: 120feet - Sonar frequency: 125 kHz Single Beam 30º -Power source: 3.7V rechargeable battery. Runs for 4continuous hours per charge. - USB port charging system. - Power output: 400 watts peak-to-peak -Transmit speed: 100 Mbps - Screen controls: Touchscreen controlsMust have :) Ice fishingAnytime fishingFish finder Depth finderFish icon and alerts .PLEASE LOOK THROUGH ALL MY ITEMS FOR GOOD DEALS COMBINED SHIPPING OPPORTUNITIES / DISCOUNTS FEEL FREE TO ASK QUESTIONS / 0FFER$ / REQUESTS / etc.