40G parallel optics transceivers (40GBASE-SR4) supports 4x10G modes, making new parallel optics active equipment compatible with existing 10G transceivers. Parallel optics 40GBASE-SR4 uses 8 out of 12 MPO interface fibers, transmitting 4 x duplex (DX) channels (4 x transmit and 4 x receive). QSFP+ to SFP+ fanout is 8 x fibers MPO to LC (DX) ruggedized fanout assembly. 15ft Mtp Om4 F To 4x Duplex Lc M Fanout Fiber Optic Cable.