The AJA 12GM is a 12G-SDI to/from SDI muxer/demuxer, converting between SDI standards for facilities bridging legacy and current infrastructure. It multiplexes Quad 3G-SDI into a single 12G-SDI signal and demultiplexes 12G-SDI back out to Quad 3G-SDI, supporting resolutions up to DCI 4K and letting multi-link signals run over fewer cables while keeping newer standards backward compatible with legacy SDI gear. The 12GM converts SMPTE 2082 inputs and outputs to SMPTE 425 configuration, and SMPTE 425M A to/from SMPTE 425M B; when the input is SMPTE 292M, all outputs default to 1.5G SMPTE 292M. Every signal is fully equalising and reclocking with jitter attenuation, then amplified to preserve integrity over long cable runs. A DWP-U-R1 power supply is included.