The iSilencer+ uses Active Noise Cancellation II technology. It decreases noise in a similar way to noise-cancelling headphones. It uses REBalance tech to get rid of clicks and distortion. Low-ESR tantalum capacitors have been added for improved input and output filtering. Filtering capacitance has been increased 10-fold. As well as plugging the iSilencer+ into the active USB port between the computer and DAC, it can also be plugged into unused USB ports too. This will further reduce radiated EMI.Each time the number of units (and therefore the number ANC II circuits) is doubled, noise reduction capability also doubles.