The Dual Multiplier comes equipped with two four-quadrant multipliers. All inputs are DC-coupled. Attenuators allow level adjustments. The inputs of the multiplier located at the top of the front panel are labeled X and Y. Its output is called XY. The inputs of the lower multiplier are named A and B. Accordingly, the output is called AB. As long as no cables are plugged in, input A receives its signals from output XY. Input B is connected to input Y.