2x2, 840nm, 80/20 split ratio pigtail fused coupler with 250um OD buffered 5/125µ SM fiber terminated with an Angled FC/APC connector on input port T, and an ultra FC/UPC connector on input port R. The 2 output ports are terminated with 8 degree slant 1.8mm OD ferrules . The fiber on the input port (port T) is 700±20mm long and in RED colour. The fiber on the 80% output port (Port 1) is 420±10mm long and in RED colour. The fiber on the 20% port (port 2) is 285±10mm long. The fiber on the return port (port R) is 745±10mm long with 0.9mm OD tubing added from the FC boot end to within 50mm of the coupler body. SP2: The length difference between the port 1 fibers and port 2 fibers is to be 135mm ± 5mm. .