This ion-activated Castle Thrust has an affinity for metal that enables it to penetrate deeper and faster than regular penetrating oils. A special blend of lubricants assures constant lubrication and resists high-temperature breakdown, even under the most severe conditions. Castle Thrust foams in order to minimize run-off and keeps more product working on the rusted part, and will not “burn off.” 3-pack. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.