The Shure UA400 1/4 Wave Antenna is specifically engineered to enhance the performance of U4S, U4D, and UC4 receivers. This antenna operates within the 774 - 862 MHz frequency range, making it ideal for a variety of wireless applications. Its robust design ensures reliable signal reception, providing users with clear audio quality and extended range. Whether you're in a professional audio setting or a live performance environment, the UA400 antenna is a crucial accessory for optimizing your wireless system.