Although the US army air corps already had its own insignia (a star design similar to that still used at the start of WW2), when the US joined the allies in WW1, it was decided that they should adopt similar style markings to the British and French, and the Red/Blue/White roundel was adopted.

These decals are scaled to represent 30", 36" and 48" diameter roundels in 1/300 scale. The actual diameters are 2.5mm, 3mm and 4mm.