KandW NanoTechnology Permanent Head Gasket and Block Repair uses nanoparticles that are one millionth the size of a millimeter. These particles fill in the crevices that other products cant, making a stronger, more solid bond thats permanently hardened to the surface area. Features and Benefits: - A permanent repair - Does not rely on cooling system pressure to maintain seal - Repairs head gaskets, cracked engine blocks, intake gaskets, cylinder heads, freeze plugs, heater cores and other cooling system leaks - Nanotechnology provides the tightest molecular bond - For gasoline or diesel engines - Treats 4, 6 or 8 cylinder engines - Works on aluminum, cast iron, copper, brass and plastics - Double your money back guarantee offered by manufacturer