Radio Magnetic Course Indicator ID-250A/ARN

Here is a Radio Magnetic Course Indicator which was used in a variety of US military aircraft of the 1950s, 1960s and 1970s, including versions of the F-100 Super Sabre, F-102 Delta Dagger, B-52 Stratofortress (see photo of RMI on B-52 instrument panel), C-130 Hercules, and UH-1 Bell Huey.