The NIBCO® Press System® copper cap features an inboard bead and EPDM O-ring. Simply applying pressure from a pressing tool tightens the O-ring onto the tube, ensuring a clean, watertight seal in seconds with no flame, solder or flux. The cap has a press connection. The fitting is used to fit over the end of pipe to seal the end. NIBCO press fittings are the fastest, easiest way to join copper tubing. NIBCO® Press System® fittings are designed to join with seamless copper water tube in residential and commercial potable, hot, chilled and process water applications for plumbing and HVAC systems. The press fittings can also be installed underground. The NIBCO® Press System® is user friendly, quick and easy to install. When properly crimped a unique "N" witness mark is clearly visible. Please refer to NIBCO technical data sheets and catalogs for engineering and installation information. 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. In addition to its inherent qualities of beauty, durability and low maintenance, copper's reusability makes it an ideal application in sustainable projects. NIBCO® Press System® copper fittings are backed by a 50-year limited warranty. Because of its longstanding reputation for innovation and precision in design and manufacturing, NIBCO is the preferred brand in the industry.