CAROL Professional Active Handling Noise Cancelling Vocal Microphone_AC Series   The world's first active handling-noise cancelling microphone, build-in CAROL exclusive patented AHNC capsule to reduce handling noise. Elegant thin and curve design which contain an internal hum-bucking coil to reduce EMI/RFI noise for professional stage performance or karaoke. With CAROL patented slide potentiometer switch, which has good effect on inhibiting acoustic shock when the switch is turned on and off.