Superior single barb technology that provides a leak-proof seal. Ideal with flexible tubing. Flexible, smooth 2 1/4 in. flat disc base. Bag ports, also known as port plates and port discs, are designed to be ultrasonic or thermal welded to medical and bio-reactor bags of like material. These single-use bags are used to transfer drug compounds, cell culture and fermentation as well as other media and fluids in the bio-pharmaceutical industry.