RN Composite Male Branch Tee accommodates Metric Tubing O.D Ranging from 4mm to 16mm, Inch Tubing O.D Ranging from 1/8″ to 1/2″. Accommodate Thread Ranging from 1/8 NPT to 1/2 NPT. One touch tube fittings male branch tee is widely used in pneumatic circuit. In line connection of tubing to a female threaded port. External tightening with a flat wrench.