The ENET QSFP-40G-ER4-A-ENC Arista Networks Compatible QSFP+ transceiver operates at 40Gbps over Single Mode Fiber at 1270/1290/1310/1330 with a maximum reach of 40 kilometers. Each QSFP-40G-ER4-A-ENC is 100% compatible in fit, form, and functionality compared to the OEM product. Our extensive quality control measures begin with physically inspecting each module, verification of hardware type, wavelength, transmit power, receive power, and full optical monitoring functionality (if applicable). Each QSFP-40G-ER4-A-ENC is individually programmed in-house and then Spirent® tested for performance and functionality as well as compatibility tested in target Arista Networks platforms. Old and new revisions of Arista Networks operating software are used for testing to ensure 100% compatibility. Our test lab contains Spirent® traffic emulation equipment, along with more than 80 of today''s most popular switches, routers, and servers. All ENET Arista Networks compatible transceivers are MSA compliant for seamless integration and RoHS compliant for environmental conformity. All ENET transceivers are backed by a Lifetime Replacement Warranty.