ART PB4X4 4x4 Pro USB Series Power Distribution System SLIK the PinMic Long features a miniature Bundle:Video Assist Recorder Only the PinMic Long features a miniature condenser capsule with an omnidirectional polar pattern and audio fidelity well suited for professional recording A 4 line Adaptive Comb Filter provides high quality decoding of composite sources All PRO USB SERIES models have an additional internal discrete module called APF™ (Advanced Power Filtering) which filters out digital and dimmer hash as well as any high frequency noise that is above the audio range but by using a high power discrete design we were able to create a filter that stays effective over the full operating range