There are two HD-EXT models – the HD-EXT1-C and HD-EXT2-C. The HD-EXT1-C includes a compact HD transmitter and receiver that carry HD digital video and audio, plus two-way RS-232 and IR control signals, simultaneously over a single STP cable. It supports HDMI with Deep Color and 3D, 7.1 channel HD lossless audio, DVI and DisplayPort components, and resolutions up to 1920×1200 and 1080p/60.
For applications requiring the extension of analog audio signals along with HDMI signals, the HD-EXT2-C substitutes the RS-232 and IR control with stereo analog audio support. Connecting an additional STP or UTP cable between the HD-EXT transmitter and receiver enables analog audio for devices that may not support digital audio capability.