The myDAQ Attenuator Shield FRI-2110-1B provides an attenuation of divide by 1,000 or 10,000 from the outputs of AO 0 and AO 1. This shield goes onto the myDAQ BNC adapter for x10 oscilloscope probes (FRI-2100-1). They are differential signals with a millivolt or microvolt level to input to a physiological amplifier. They can come from a LabView signal generator or a PhysioNet file. Therefore, a physiological amplifier can be tested without having to connect a subject with electrodes. In the photo the shield is connected via safety cables to a Grass physiological amplifier. The amplifier’s output is connected to the BNC input AO 0 that could be seen on an oscilloscope type display.