8/12/24-Fibers MPO Fiber Loopback Module MPO Loopback modules provides a looped signal to test the transmit and receiving functions. It used widely within testing environment especially within parallel optics 40 and 100G networks. 8F MPO Fiber Loopback Module allows verification and testing of transceivers featuring MPO interface – 40GBASE-SR4/CSR4 QSFP+ devices. 12F MPO Fiber Loopback Module allows verification and testing of transceivers featuring MPO interface – 40GBASE-SR4 QSFP+ or 100GBASE-SR4 devices. 24F MPO Fiber Loopback Module allows verification and testing of transceivers featuring MPO interface – 100GBASE-SR10 CXP/CFP devices. Loopbacks are built to link Transceivers (TX) and Receivers (RX) positions of MPO transceivers interfaces. MPO loopbacks can facilitate and speed up IL testing of optical networks segments by connecting them to MPO trunks/patch leads.