Valve oil is a specialized lubricant used primarily for brass instruments, such as trumpets, trombones, and French horns. It helps to keep the valves moving smoothly, preventing them from sticking and ensuring optimal performance. The oil is typically made from a blend of mineral oils and additives that enhance its viscosity and longevity. Applying valve oil is a simple process. Musicians usually place a few drops of oil on the valve casing and then work the valve in and out to distribute the lubricant evenly. Regular use of valve oil is essential for maintaining the instrument's functionality and extending its lifespan.