SFP 100/1000Base-T transceiver (also purchase SFP-GbE upgrade) allows the SFP port on E3Switch Ethernet to DS3/E3 converters to connect to RJ-45 Cat 5 cable up to 100m. Finisar model FCMJ-8521-3 or equivalent. Availability: Usually ships the next business day SFPxcvrCopper$100.00 Copyright (c) 2011, E3Switch LLC, all rights reserved.