... ,telecommunication equipment,and test equipment. Oppton's 1x2,1x3,1x4,1x5,1x6,1x7,1x8......Single window/Dual window FBT Coupler/splitter family has ... Fiber coupler(FBT Coupler/Splitter) 1xN /NxN tree/star Fiber Coupler(FBT Coupler/Splitter) 1x3/3x3 single fused optical coupler(FBT Coupler/Splitter) 1x4 single fused optical coupler (FBT Coupler/Splitter) Fused ...