Thank you for viewing. This is a set of 3 piston buttons for euphonium. These are gold-colored piston buttons with clear lacquer finish on the metal parts, and inlaid with abalone shell that shines in blue and green. They have a beautiful, multi-colored luster, adding a touch of elegance to your instrument. While these are for Adams euphoniums, they can also be installed on Wilson and Besson euphoniums. *For Besson, we have confirmed installation on German-made models. We have not confirmed installation on British-made models. This is a set of 3, but you could install these on the 1st, 2nd, and 3rd pistons, and use the original button or a button from another company like BRAKUL for the 4th piston. This product is not available in Japan and was imported from overseas. The purchase price was $107.35. For your reference. #euphonium #euphonium #pistonbutton #abaloneshell #adams #Adams #willson #Wilson #besson #Besson