Valve Oil (Trumpets, Baritones, Tuba)
Valve oil is essential to keeping a brass instrument in good working order by providing lubrication for the pistons valves and casings. Similar to your car engine, the oil allows for the pistons to move freely while also flushing away dirt and grime that accumulate over time. A bottle should be in your students case at all times.
Highly Recommended: Al Cass "Fast", Blue Juice, Yamaha.