Ultra-Pure Linkage, Lever and Key Oil is used for rotary valve mechanical linkages, ball joints, levers, keys, triggers, etc. It is excellent on all threaded parts, such as valve cap threads and threaded bells. Use also as woodwind key oil for clarinet, saxaphone, flute, oboe, bassoon, etc.If your bearings and valves are worn or a little leaky, then use our Linkage, Lever and Key Oil on the bearings, and use our Light Bearing Oil on the rotory valve surface (put a few drops down the slide tubes).Synthetic, non-toxic, odourless and long-lasting.