For piston valves, we recommend Yamaha YAC RVOX Regular Synthetic Valve Oil. It has a medium weight that allows the oil to work with nearly every piston valve out there. Yamaha formulated YAC RVOX oil to provide fluid playability and major staying power. For the player, that means you’ll enjoy quick and responsive playability that lasts longer than other conventional oils. This oil is a great choice for players of all skill levels, from students to professionals.