GLC-SX-MM-RGD=Cisco Rugged Sfp - Sfp (Mini-Gbic) Transceiver Module - Gige - 1000base-Sx - Lc/Pc Multi-Mode - Up To 550 M - 850 Nm - For Cisco 2010, 2520, 3270, Catalyst 2960, Ess9300, Industrial Ethernet 30xx, Mwr 2941