This is a type of adjustable clamping lever made by the Italian company Elesa & Ganter. The part code identifies the style, size, and other features of the product. The "DVC" part of the code indicates the product is a clamping lever, while the "3-25-20-20-M6-40" identifies the specific style and size of the lever, including the material, the base thread size and pitch, the length and width dimensions, and the torque rating. This particular lever is made of stainless steel, has a 6mm base thread, is 25mm in length, 20mm in width, and has a maximum torque rating of 40Nm.