The FP410 uses Shure IntelliMix to dramatically improve audio quality by providing greater gain-before-feedback, reducing the pickup of ambient noise and reverberation, and virtually eliminating comb filtering effects. IntelliMix^® combines three key features: NOISE-ADAPTIVE THRESHOLD activates a microphone for speech but not for constant room noise; MAXBUS limits the number of activated microphones to one per talker; LAST MICROPHONE LOCK-ON keeps the most recently activated microphone open until a newly activated microphone takes its place. Primary applications include video production, broadcast, conference recording, and field production. One rack space high, accessory rack ears supplied. Battery (two standard 9-volt alkaline) or 120/230 Vac power.