Mahle is the company that makes them, its their Gold Series that are designed for FRM bores. Porsche has been using them for ages as they as well share the FRM liners.

For the past few months people havent trusted them much because only a few people have got them to work without damage. After having built a motor with the mahle pistons i think i know why most people dont get them to work. Just follow the data sheet that comes with the pistons to the tee and you will be fine.