The product is a 1/2-13 UNC-2B thread plug gage, specifically designed for measuring the dimensions of threads. This gage is used for inspection purposes to ensure that the threads are accurately machined and meet specifications. The product includes both a go gauge (P.D. .4500) and a no go gauge (P.D. .4565), allowing for precise measurements to be taken during the inspection process. Thread gages like this one are essential tools in the CNC, metalworking, and manufacturing industries for maintaining quality control in thread machining.