Nibco press fittings are the fastest, easiest way to join PEX tubing systems. Nibco Press System fittings are designed to join with PEX tube in residential and commercial water distribution, radiant floor heating, municipal water supply, geothermal climate control, snow melt and drip irrigation. The press fittings can also be installed underground. When properly crimped a unique "N" witness mark is clearly visible. Nibco Press System applies the proven performance of press technology to Nibco valves and fittings - the most specified flow control products in the industry. The Nibco Press System features a full range of precision engineered copper and copper alloy fittings, commercial valves, accessories, pressing tools, jaws and chains.