They have different coloured edges (rails) that make adjusting easier. They come with a great book of instructions, that despite being written in German the photos are easy to follow even for those new to slings. They can be washed at 40C & occasionally at 60C ( but please don’t tumble dry.)
All of this creates a great ringsling that is soft straight out the pack, & despite being on the thinner side is still incredibly supportive & comes in a wide variety of gorgeous colours (the pictures don’t do them justice!).