This is a sharp, metal disc that was shipped in a plastic bag with no protection(bubble wrap, cardboard, paper, nothing) and was supposed to include the screws to attach it to the wheel. Because of this poor packaging the plastic bag inside was ripped from the disc, and the screws were lost bc the disc also sliced a hole in the plastic that it was wrapped in and they fell out. The hole in the outer packaging was about 4 inches long, im surprised the whole disc didn't fall out and I got an empty plastic bag with a hole in it