The first fish finders were analog flashers using a circular dial with a spinning arm and LED light to display fish and structure. While these systems were not as easy to read as a modern LCD graphing fish finder, a flasher provides the most accurate image of fish below the transducer. Today, graphing fish finders have reduced the delay between receiving the sonar signal and displaying the information on the screen, but many ice fishing anglers still prefer the reliability and versatility of a flasher.   Flashers can be adjusted to provide detailed information about the fish and type of structure below the transducer. Experienced anglers can interpret the return signal to watch their lure and see how the fish react. Flashers are usually smaller and lighter and draw less power than a large digital display, so they are easier to carry and power with a battery.