Working on a refrigeration or air conditioning system? This Copper Pipe Union Nut Set is designed for 10mm copper refrigerant lines. The set includes union nuts with SAE 3/8 threads, making it easy to connect or repair lines in your AC or fridge unit. Made by Mariel (part D17010-3/8) and manufactured in Iceland, these fittings are brand new and built to handle the pressures of refrigeration systems. They're compatible with OEM reference numbers for copper tubing and refrigerant lines. Whether you're a professional HVAC tech or a skilled DIYer, these quality fittings ensure a leak-free, secure connection. Keep your cooling systems running efficiently with this reliable union nut set. A small part that makes a big difference in your repair job.