A seven exquisite interface microphone microphone interface CZJ-218, its bottom is zinc sheet metal, the net cover is a certain hardness of the steel mesh molding, so beautiful in appearance, it uses reverse interface to remote pick-up and its higher receiver sensitivity and receiving angle is 120 degrees, pick-up distance can reach 6 ~ 8 meters. Types of technical indicators: back electret condenser microphone (three back electret Hugh sound head) maximum input sound pressure level: 120dB (THD is less than or equal to 1%, and 25 Ohm load) directivity: Super heart-shaped signal-to-noise ratio: 72db (1KHz@1Pa response: the sensitivity of 40~16000Hz: 40mV/Pa (as + 2dB, @1KHz 25 Ohm load. DB=1V/Pa) output negative resistance: 200 ohm (@1KHz) power supply: 48V phantom power exterior size: Phi 105 x 75 x 27mm