Shure AD2/SM58-G57 Digital Handheld Wireless Microphone Transmitter with SM58 Capsule 470 to 616 MHzShure AD2 Overview The Shure AD2 SM58 is a digital handheld wireless microphone transmitter compatible with Axient Digital series receivers. The AD2 SM58 comes equipped with the legendary SM58 dynamic capsule, an industry standard for vocal performers and presenters. The capsule features a cardioid polar pattern that minimizes background noise and feedback, and its brightened midrange and bass roll off gives you that sought after warm and clear vocal