The OTR-301-AD is a compact, cost effective fiber optic extender pair capable of extending HD video up to 3G-SDI with bi-directional analog audio and serial data over fiber. Extend signals from 270 Mbps up to 3 Gbps over 30 Km on a single SM fiber. Meets SMPTE SDI standards maintaining error free transmission of SMPTE 424M, 292M, 259M and ASI over the entire 30 Km distance. The OTR-301-AD provides error free transmission with RP-198 pathological patterns. Along with SDI video, bi-directional analog audio and RS-422/485 serial data are sent on the same fiber. The units come standard as stand-alone units, however, using model OTR-1U-C or OTR-4U-C they can also be mounted in a 1U (up to 4 units) or 4U (up to 16 units) chassis with redudant power supplies. The flexible design of the OTR 30x series makes it the perfect solution any application that needs rack mounting or stand- alone units. The OTR-301-AD has an extended temperature range making it a good solution for mounting in NEMA enclosures.