SM31FH Fitness Headset Condenser Microphone Wireless headset microphone featuring moisture-repelling hydrophobic construction for use in fitness instruction. Best suited to: Vocals Condenser Cardioid Tech Specs TRANSDUCER TYPE : CONDENSER POLAR PATTERN: CARDIOID FREQUENCY RESPONSE from: 45 Hz FREQUENCY RESPONSE to: 20 KHz SENSITIVITY (dBV/Pa): -50 dBV/Pa