Features: when air conditioning is installed, expand copper tube, make two copper tube mutual link. (To be installed on hand electric drill.) A full range of forging tools makes it easier to expand HVAC pipes, the forging stopper will provide a large swaging depth to achieve a perfect fit. made of bearing steel. It has high and uniform hardness and wear resistance, and high elastic limit. 6 piece set, with the most common HVAC pipe diameter: 1/4 inch, 3/8 inch, 1/2 inch, 5/8 inch, 3/4 inch 7/8 inch, 6 different sizes per set of your choice to meet your needs. Whether it is a beginner or a professional, it is an for ideal choice for installers. Specifications: Material:Metal Dimension:Approx.7/8（22.2mm），3/4（19mm），5/8（15.9mm），1/2（12.7mm），3/8（9.5mm），1/4（6.3mm）/ 7/8（0.86inches），3/4（0.74inches），5/8（0.62inches），1/2（0.49inches），3/8（0.37inches），1/4（0.24inches） Net Weight: Approx.180g Package Includes: 1 Set Drill Bit Expander (Including 6 Pcs) note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item.