Hetman Key Lubricant Medium Key Lubricant Medium All Hetman Musical Instruments lubricants offer superior lubricating qualities, are longer-lasting than other lubricants, and are completely compatible with conventional petroleum-based lubricants, thereby avoiding potential gumming problems The viscosity of each lubricant is carefully calculated for its specific purpose and assures both a fast, positive action and vital protection against wear and corrosion This synthetic lubricant keeps woodwind keys moving quickly and quietly Frees sticking keys by penetrating into hinge tubes