ACDelco 17D666M Professional Semi-Metallic Rear Disc Brake Pad Set Tested to SAE J2784 for braking effectiveness, along with Noise/Vibration/Harshness (NVH) and durability/wear testing for assurance of quality Ceramic, semi-metallic, and organic formulas provide safety and reliability for a range of vehicle applications Integrally molded - friction material molded to backing plate for bond integrity Premium shims, slots, and chamfers help to diminish noise, vibration, and braking harshness Stamped backing plate allows for proper pad movement within the caliper assembly, reducing noise, brake pulsation, and helps to protect against premature wear