The Libra Supply Press System wrot copper union features an inboard bead and EPDM O-ring. Simply applying pressure from a press tool tightens the O-ring onto the tube, ensuring a clean, watertight seal in seconds with no flame, solder or flux. The union has press connections. It is used to allow repair to the line without damage between two press connections. Libra Supply press fittings are the fastest, easiest way to join copper tubing systems. Libra Supply 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 Libra Supply Press System is user friendly, quick and easy to install.