Module A-183-5 is a simple passive quad attenuator. Passive means in this context, that each unit is made of two sockets and a 50k linear potentiometer only. There are no active parts like amplifiers or buffers and no power supply is required.
This is how the A-183-5 works: At the output socket appears the attenuated input signal, i.e. zero level at the fully CCW position and max. level and the fully CW position.
Adjustable level of CV or audio signals to control other modules that do not have attenuators available.