The Shure WH20QTR is a rugged, light-weight, dynamic headset microphone that provides high-quality voice pickup. It fits securely for active microphone users, such as aerobics instructors and musicians, with low visibility for stage appearances. The WH20QTR is suitable for any voice communications application where comfort and reliability are required. This provides greater gain-before-feedback and isolation from ambient noise and other unwanted sound sources, such as air-conditioning, musical instruments and loudspeakers. A carefully shaped frequency response includes a voice-frequency presence peak and a low-frequency rolloff to compensate for the proximity effect inherent in cardioid microphones during close-talk operation.