Raymarine E70294-US Dragonfly-4 Pro Sonar/GPS with US C-Map Essentials Optically bonded for sharp color, wide viewing angles and no internal fogging Includes US lakes, rivers and coastal maps; Includes transom mount CHIRP transducer with temperature sensor; MicroSD memory card reader for saving sonar screen shots Dual-channel sonar - wide-spectrum CHIRP DownVision sonar for photo-like images and a second CHIRP conventional sonar channel for targeting fish 4.3" All-weather, high-definition LED backlit display Stream live sonar data to your smartphone with Raymarine's Wi-Fish mobile app; With the Wi-Fish you can rewind, save and share the day's catch with friends on your favorite social networks