This product can drop a little with the piston wall to prevents the rust produced by the water vapors and reduce the wear and tear. Features: Super pure valve oil for music instrument. Compact design, portable and easy to carry around. Suitable for trumpet, horn, trombone, brass instrument, etc. Keep valves and piston moving quickly and smoothly. Fast acting oil, long lasting. Can well lubricate the moving parts of the instrument to reduce the friction damage, extend the life of the instrument. Specifications: Item name: Valve oil Capacity: 30ml Usage: Brass Instruments Color: transparent Package size: 90 * 50 * 30mm / 3.5 * 2.0 * 1.2in Package weight: 30g / 1.1ounce Packing List: 1 * Valve Oil