As an Industrial and Scientific worker, I was highly disappointed with these finishing products. As my tests showed the Zona 37 942 polishing discs did not live up to their advertised capabilities .the pros were few and far between - maybe a slight improvement on low-demand surfaces. However, the cons were far greater: unacceptable durability, uneven abrasion, and poor adhesion to my equipment. i wouldn't recommend wasting YOUR money on this product..