SFP fiber-optic transceiver (also purchase SFP-GbE upgrade) allows the SFP port on E3Switch Ethernet to DS3/E3 converters to connect to 1310nm, 9/125µm SMF up to 10km. Finisar model FTRJ1319P1BTL or equivalent. Availability: Usually ships the next business day SFPxcvr1319$150.00 Copyright (c) 2011, E3Switch LLC, all rights reserved.