Union, Connector, Cross, High Pressure, 1.0 mm Through Hole with 1/4-28 Screw Threads, Carbon PEEK Endure, Round with an Internal X. Use with 1/16 Tubing. ARE-Applied Research brand. 2/EA.
This "Union" is used to connect PEEK or stainless steel tubing with the same size connectors on all ends in the high pressures zones of HPLC systems. A "Cross (X)" internal flow pattern is often used to split flow into two or three directions or to combine two or three streams into one.