The Shure PGX24/SM58 Hand-Held Wireless System delivers unmatched performance and ease of use to anyone looking to step up to wireless. The PGX4 receiver has features like Automatic Frequency Selection and Automatic Transmitter Setup that get you up and running, hassle-free. Shure's patented Audio Reference Companding delivers crystal-clear sound beyond the limits of conventional wireless technology. This package includes the PGX4 receiver and the PGX2/SM58 mic/transmitter.