Intel Ethernet Server Adapters; X520-SR2 E10G42BFSR MM#900137 (Dual SR), X520-SR1 E10G41BFSR MM#900141 (Single SR), X520-LR1 E10G41BFLR MM#900140 (Single LR) and X520-DA2 E10G42BTDA MM#900139 (Dual DA) (Spring Fountain Retail skus), PCN 109650-00, Documen