This is an authentic manufacturer-sourced replacement part which is made for Waring blenders. The coupling is the part of a blender that transfers power from the blender's motor to the blade assembly. Over time, it may wear out, get damaged or lost eventually requiring a replacement. It is made of high-quality metal and is sold individual...Read morely. Replacing it is a simple task that does not require any special tools. Refer to the owner's manual and the appropriate diagram of your model for the correct application.