hm, well what can I say

Product review ok: .... no beautifully finished at the edges of the ridge is not polished and very sharp.
Actually, it is so, is specified in the product description: the disc has 3 mm, "of 0.2 mm pure aluminum" between any plastic or something like that, but not a pure aluminum plate of 3 mm ..... Qualitatively, I say nothing, of it is gray aluminum :-))
Am superior whether I should install it at all, because I do not know how the passage of time, the aluminum behaves.