The OTC 897A Thread Chaser is a comprehensive set designed for automotive use, featuring 6 dies ready to use. This SAE measuring system tool is manufactured by OTC in the United States, making it a reliable choice for thread chasing tasks. The set includes everything needed for efficient thread chasing, making it a valuable addition to any mechanic's toolbox. Nice clean tool all of the 6 have no chipped teeth. Social Security # etched on the tool.