Core made of High-Carbon AISI 52100 Chromium Alloy Steel features higher wear resistance, fatigue strength and steel hardness, Engineered with Heat-Flowed cast iron to give our wheel cylinders the ideal balance between tensile strength and hardness, TQ OE-matched material gives our spring kit the ideal balance between tensile and hardness and provide consistent wear, long life, and quiet operation, Premium quality MolyPro™ NLGI Grade 2 Molybdenum Grease (MoS2) to minimize wear and reduce friction providing longer lasting performance, Anodized coating provides complete 360º protection against rust, moisture and oxidation, Independently tested with Noise/Vibration/Harshness (NVH) and durability/wear testing; resulting in high quality and reliable products, Exclusive multi-lip seals are made with ProSeal™ Nitrile Rubber (NBR) which can successfully function at high delta of temperatures while retaining its flexibility and sealing performance, Kit Includes: 2x Rear Kugel Wheel Bearing (Both Side) + 2x Rear Kingstar Drum Brake Wheel Cylinder (Both Side) + 1x Rear Top Quality Drum Brake Hardware Kit, Kit Variations: K7D-100487