Red stars with yellow border and a very fine black trim added. These are the same design as 300-RU-4, but with the addition of a very fine (one six-hundredth of an inch) black edge around the design. This is done for obscure technical reasons, but the end result is a decal that shows up somewhat better, especially on dark surfaces. That said, the difference isn't as significant as on the 1/600 size stars.
These decals are scaled to represent 30", 36" and 48" height markings in 1/300 scale. The actual dimensions are approximately 2.5mm, 3mm and 4mm. While primarily intended for 1/300 scale fighters, they're also ideal for heavy bombers in 1/600, and even for use on larger scale vehicles.