1x2 Optical Coupler Low insertion loss, low PDL High directivity, high return loss All-optical structure 1x2 optical coupler SM, single window 1310 or ... Standard-NC (tube) Tree structure Stainless steel tube 1x2 optical coupler, SM, single window, standard-NC (tube), 9/ ... FeatureLow insertion loss, low PDL. High directivity, high return loss. All-optical structure. Stainless steel sleeve.Electrical ...