This part is part of a series of adjustable handles manufactured by Elesa & Ganter. The number refers to the size, shape, and design of the handle. The first two digits, "2-30", refer to the handle diameter. The following two digits, "18-25" refer to the length of the handle from the center. The letter "M" refers to the design of the handle; in this case, "M8" refers to a particular type of mushroom-shaped handle. The next two digits, "20-70", refer to the distance between the handle and the mounting surface.