GLS Audio Vocal Microphone ES-58 & Mic Clip - Professional Series ES58 Dynamic Cardioid Mike Unidirectional (No On/Off Switch) - 3 PACK Uni-Directional Dynamic Vocal Microphone Frequency Response: 50 Hz - 15,000 Hz Sensitivity: -72dB at 1,000 Hz (Open Circuit Voltage) Can be used with Lo-Z XLR 3 Pin Balanced & Hi-Z 1/4" Impedance: 300 ohms at 1,000 Hz