From the manufacturer:
The AI028 Voltage Controlled Matrix Mixer is a 6-input, 6-output Matrix Mixer, with 36 VCAs to control how much each input is fed to each output (0-5V). The Module can distribute audio and/or control voltage, and has a dedicated 5V output for use with passive or active attenuators for manual volume control.Features include:
Kits include all parts needed to build and mount the AI028 Voltage Controlled Matrix Mixer Interface including: