According to The Body Shop Webpage:
A high-density foundation brush that ensures just the right amount of loose powder is held in place between the bristles for progressive release and a smooth, even coverage. Rounded cut hairs are designed to allow circular movement across the face. Features a specially designed handle that fits easily into the palm, to allow appropriate pressure and flexibility.
While I didn't really like The Body Shop's Mineral Foundation, I think that their Kabuki or The Body Shop - Nature's Mineral Foundation Brush is a really good brush, I've used it to apply my other mineral powders and I've really liked it, it is soft, not scratchy and I didn't have any problems with fall outs or stainning.