I bought these rotors in November 08, a full set front and rear for my 02 F150 4WD truck, have used them for a couple of months after each time , when driving slowly I started to hear an annoying noise, I had to apply the brakes (the recommended EBC green material ceramic pads were also installed). I decided to take my truck to the brake mechanic after getting really pissed off only to find that the front left rotor has a nice complete circular groove about 1/8 inch deep on the inside and the raised area on the pad is visible is. I was very disappointed not to say amazed as was the mechanic at my misfortune as these rotors proved to be virtually indestructible according to the product specification and the fact that they cannot be machined and are not available individually. Now I only have a wasted, useless set of rotors. At least I didn't throw the box away. Very, very disappointing.