Quite a good price, because others sell them for around 3 euros each, so it's worth it to buy in bulk. Its job is to clean metal or whatever else you want (I haven't tried wood) with the angle grinder. If you learn how to use it, you won't make a dent but a perfect surface. I actually use it for polishing to achieve a good result in certain areas, which I then finish with the eccentric polisher to make it perfect, but also to clean up any welding protrusions.