The MLP Solid Film Lubricant Pen meets the performance of Mil-Spec requirements. MLP is a semi-permanent, lacquer-like coating containing molybdenum disulfide and corrosion inhibiting pigments. This air-drying material prevents corrosion, galling, seizing and fretting. MLP is a low-friction coating that exhibits long wear life when operated at -320F to +300F. For internal firearm application only.