Custom brass 19mm female joint making tools made in USA.This 10:1 ratio OG reamer is designed by Dawg House Glass by glass blowers for glass blowers. This tool is designed to help you make those next to perfect 19mm female glass on glass joints fully worked.We sale a full tool line from pushes to reamers as well as tree jigs and joint making tools. We have several available soplease email with questions if you don't see what you are looking for. Thanks for your support!