The XSW 1-825 Dual-Vocal Set with Two 825 Handheld Microphones from Sennheiser includes an EM-XSW 1 dual stationary receiver with internal antennas, two SKM XSW transmitters with mute switches, two MZQ 1 microphone clips, an NT 12-5 CW power supply, and four AA batteries. The analog UHF dual-channel wireless system can be used in several applications for singers, presenters, DJs, churches, and schools. Designed with ease of use in mind, the XSW 1 Dual-Vocal Set features automatic frequency management and synchronization via remote channel for easy setup. In addition, it is equipped with up to 10 compatible channels.