Yamaha Regular Synthetic Valve Oil is based on a newly developed synthetic formula that is more consistent than mineral-based oil to provide superior performance in all playing environments. The oil is made up of even-sized molecules to allow the oil to evaporate smoothly, guaranteeing a longer life with extremely responsive action. The Regular Synthetic Valve Oil is designed for instruments with regular to tight valve tolerances, such as custom and professional trumpets and is the same oil included with all Yamaha Piston Valve instruments. 38 ml.