The product is a Starrett depth micrometer, known for its precision and reliability in measuring the depth of surfaces with a mechanical reading. It is specifically designed for metalworking inspection and measurement, making it ideal for CNC machining, metalworking, and manufacturing industries. The addition of a 16 inch Mitutoyo depth rod indicates that the set includes a high-quality and accurate depth measuring tool from a reputable brand, ensuring accurate and reliable measurements for a variety of industrial applications.