The Shure SM58 S is identical to the SM58 with the addition of a convenient on/off switch. With its unmistakable sound quality and unsurpassed reliability, the SM58S dynamic mic has been a standard on stages throughout the world for years. A carefully tailored frequency rise at about 4000 Hz makes the vocals stand out in the mix and yet keeps them smooth and “easy on the ears.” It’s no surprise that the SM58S is the most popular mic in the world. The SM58S has a cardiod (unidirectional) polar pattern a 50-15000 Hz frequency response, is a low-impedance mic and includes a mic stand adapter. Consistently the first choice of performers around the globe, the SM58 vocal microphone is a genuine world standard and a true audio legend. The Shure SM58 is a unidirectional (cardioid) dynamic vocal microphone designed for professonal vocal use in sound reinforcement and studio recording.