Waters® tubing and fittings are carefully designed to provide leak-free connections, with low dead volume, and minimal band spreading. For best performance, these components must be clean, and designed to work together. The geometry of the ferrule and the conical port that it is used with must match, as well as the diameter of the tube and the fittings. A variety of materials, lengths and diameters are available to provide the flexibility you need when you set up and maintain your system. Part number WAT033391 has been replaced by this new part number WAT022996.