Penetrate HD frees stuck fan blades, blower shafts, pulleys, rusted nuts and bolts - any frozen, rusted, or seized metal part! New low surface tension formula penetrates into the smallest spaces and breaks and dissolves the bonds of rust and corrosion. Lubricates and protects metals with a dielectric strength to 40,000 volts (Low VOC formula for California - 31,000 volts). For industrial and professional use only. Specially formulated with new low surface tension technology to seep into the smallest cracks, crevices, seams, or threads of rusted, seized, and corroded parts. Quickly dissolves the bonds of rust, corrosion, carbon deposits, gums, varnishes, and grease to free the metal parts. Penetrate HD displaces water and leaves a lubricating film to protect metal parts and further prevent rust and corrosion. Unique formula uses capillary action to penetrate into the smallest spaces. Results are amazing.