Module A-150-8 contains eight manually/voltage controlled switches.

Each of the eight switches has a manual control button (Man.), a control voltage input (CV), a common Out / Input (O/I), and two In / Outputs (I/O1, I/O2).

The switches are bi-directional, i.e. they can work in both directions, so can connect one input to either of two outputs, or either of two inputs to one output.

Two LEDs show which in / output is active (i.e. which is connected to the common out / input). In addition the LEDs are used for the programming of the module.