Bose ControlSpace ESP 4x4 mic/line input/output card series II
Occupies two audio slots. Provides four microphone or line-level inputs (software-selectable), and four line-level outputs. Expands the number of available analog I/O channels. ESP-00 II can support a total of four 4x4 cards for a total of 16 mic/line inputs and 16 line outputs.