This set is made from very SOFT brass. It won't damage polished brass the way stiffer, rougher brushes (especially wheels) will (they're good for getting rid of really bad corrosion, but you have to be very careful not to go too deep). This set is gentle and you get multiple shapes to get into the most awkward nooks and crannies. The price-performance ratio is also great in my opinion. My only gripe (hence the 4 stars) is that the packaging is quite thin cardboard and I need help with the mess so something more durable would be appreciated.