1986 thru 1991 Porsche 928 928CS 928GT 928GTS 928S 928S4 Front & Rear Brake Disc Rotors +Pads Machined in the USA. Counter Sunk to prevent from cracking. Double Disc Ground for better braking. Drilled and Slotted to provide the most cooling. Shortest Stopping distances and better wet weather braking. No modification is nessecary. Zinc coated to prevent from rusting. Semi-Metallic Pads are designed to the OEM formula. Low Noise and Low Dust, Fade Resistant.