Thank you for looking. This is a part from a SCUBAPRO XTender diver's watch. It is a part that came out during maintenance of the main unit, and the main unit is not included. I am listing this item at the request of my father, who has retired from diving. I do not have specialized knowledge, so I cannot provide details. Please check the photos for the condition and accessories, and purchase with your understanding. If you have any questions or would like additional photos, please feel free to comment.