USource 40G QSFP+ ER4 40km Transcievers is designed for 40 Giabit Ethernet and 40 Gia Data Center. This modules comply with QSFP+ MSA SFF-8436 v4.8 and IEEE 802.3ba 40GBASE-ER4, with 1310nm duplex LC receptacle. This optic integrates 4 DFB laser transmitters, 4 APD receivers and an optical MUX/DeMUX into a small form factor package that delivers a 40Gbps data link in a compact QSFP footprint. We offer OEM ODM Multi-Vendor compatibility & functionality with Carrier-Grade high performance.