German Balkankreuz in the early war style. This design is useful for the fuselage and lower wings of most German aircraft through to 1943, when the later, more simplified, styles began to supercede it. Most aircraft had a similar style on the upper wings, but with the white rather thinner, to make it less conspicuous. Sheet 600-GE-2 is ideal for this, or use this sheet anyway if you want a more prominent looking marking.
These decals are scaled to represent 24", 30", 36" and 48" sizes in 1/600 scale. For best effect, I'd recommend using the larger sizes wherever practical. The actual sizes are 1mm, 1.25mm, 1.5mm and 2mm, so these are small decals.... While they're intended for 1/600 aircraft, they will of course come in handy for vehicle markings in larger scales as well.
These designs are of course supplied on the same paper as all of the others (actually a *very* pale blue) - they've just been given a coloured background so that the white is more readily visible in the picture.