Tuning slide grease gives a good grip and seal to your tuning slides.  It is formulated to work in partnership with Fat Cat Valve Oil. Its synthetic formula resists being dissolved into your valves and rotors when in contact with valve oil.  A thin smear on your slides provides enough resistance to easily move the slide, yet hold them in place.  At the same time the grease seals and protects the unlacquered tubing.