?5 Yrs' Warranty?for 30-Days Free-returned or Exchange, 5-Years long period for Free-maintenance and Lifetime long technical support . and if you have any problems, Question US for 24Hours online service. ?LR4 vs LR Single Lambda?The difference between 100GBASE-LR4 QSFP28 1310nm 10km and 100GBASE-LR QSFP28 Single Lambda 1310nm 10km is in hardware. The modulation mode of 100GBASE-LR QSFP28 Single Lambda is PAM4, while the 100GBASE-LR4 QSFP28 is non-return-to-zero code (NRZ) modulation. Products using NRZ modulation are mainly used in 4G Ethernet. The PAM4 pattern is 4 times faster than NRZ modulation in transmission. ?Breakout 4x25G?100G-PSM4 QSFP transceiver connects to four individual 25G links terminated with SFP-25G-LR-S using a MTP breakout cable, and as for 25G to 100G network speed upgrade connection, 9 fibers single mode MTP-LC Type B harness cable can be applied. ?100G QSFP+ PSM4?100GBASE-PSM4 QSFP+ transceiver module, 12 Fibers MTP/MPO Male connectors, up to 500m on single mode Fiber (SMF), long distance transmission over singlemode fiber 1310nm. Hot Pluggable, QSFP28 MSA and RoHS-6 Compliant and DDM support, I2C management interface. Class 1 FDA Laser Safety. 0°C to 70°C(32 to 158°F). ?Wide Compatibility?It's fully compliant and compatible for Dell Force10 networks QSFP28 MSA IEEE 802.3bm 100GBASE-PSM4 standards, coding as Dell QSFP28-100G-PSM4-IR.