Designed for performers who are tired of the limits of floor wedges, the PSM 400 offers hands-on control and freedom to musicians who have a limited budget for gear. With a wide range of available options - from complete Wireless and Wired systems to individual components - there is a PSM 400 that is right, rehearsal through performance, for almost everyone who performs live music. The P4R is a component in the PSM 400 family of wireless personal monitors. When used with a P4T Transmitter, it provides the many advantages of a wireless, in-ear monitoring system, including Improved Sound Quality - high fidelity without the risk of feedback, Increased Mobility - your mix moves with you, Personal Control - through volume adjustment and MixMode.