JEGS HP Drilled & Slotted Brake Rotors are an ideal upgrade over OEM for more stopping power and less warpage. The cross-drilled holes & slots (except where noted) provide an exit route for hot gasses & brake dust to reduce heat and brake fade under hard use. These high quality rotors are CNC machined, even on the non-friction surfaces, from high strength cast iron for better balance, long life and durability. Rotors should always be replaced in pairs, one left side and one right side, for maximum safety and effectiveness. Single rotor replacement is highly discouraged. Sold individually and in pairs.