Introduced more than a decade ago, Uponor ProPEX fittings remain the most reliable method for quickly and easily making watertight PEX connections with no callbacks. Capitalizing on the unique thermal shape memory of Uponor’s PEX-a Engel-method tubing, ProPEX connections get stronger over time. ProPEX does not involve making solder joints and does not require any primers or the use of solvent cement. The fittings offer a larger inside diameter so flow restrictions are minimized. In addition, ProPEX tools need no calibration. The fittings are available in both brass and engineered plastic.