Maps like this one, which shows the extent and severity of potential icing at 9,000 feet, are displayed by the Current Icing Product (CIP) system. The red areas show supercooled large droplets (SLD) that maintain their liquid state at or below 32 degrees Fahrenheit (0 degrees Celsius). These larger drops of water, found in freezing rain and drizzle, can pose a special hazard to all airplanes, so the red indicates regions that all aircraft should avoid. Starting in December 2006, pilots, air traffic controllers, and other aviation weather users were able to select different altitudes through CIP's interactive Web display to see the severity of potential icing anywhere over the continental United States thanks to an enhanced in-flight icing product developed by researchers at the National Center for Atmospheric Research.