Collect audio evidence as important as capturing video evidence, this preamp microphone is a perfect addition to any system. This microphone is compatible with devices that accept AV input, like TV, VCR, DVR。 This high sensitive mini preamp and microphone is the best for professionals, with Preamplifier IC built on board, it increases a microphone's low output voltage to a stronger, more usable level, and it features low noise, high sensitive and auto level adjustment on-board preamp circuit.