... High directivity, high return loss All-optical structure 1x2 optical coupler SM, single window 1310 or 1550 + / -20nm Standard-NC ( ... tube) Tree structure Stainless steel tube 1x2 optical coupler, SM, single window, standard-NC (tube), 9/125um, tree structure ... sleeve (Φ3*54mm), Φ0.25mm bare fiber, 1m, SC/PC connector.FeatureLow insertion loss, low PDL. High directivity, high return loss ...