Shure 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 technology delivers crystal-clear sound beyond the limits of conventional wireless systems. This package includes the PGX4 receiver and the PGX2/PG58 mic/transmitter.