The Sennheiser SKM 825-XSW-B (article 507330) is the handheld wireless transmitter from the XS Wireless 1 series, fitted with Sennheiser's e 825 dynamic cardioid capsule and operating in the B frequency range of 614 to 638 MHz. It is sold on its own as a replacement or additional microphone for an XS Wireless 1 receiver (EM-XSW 1 or EM-XSW 1 DUAL) set to the same range. The e 825 capsule is a robust vocal capsule suited to live singing, speeches, presentations, worship and classroom use, and its cardioid pattern helps reject sound from the sides and rear. The transmitter pairs to the receiver via the SYNC function, has a sensitivity adjustment range of 0 to -30 dB in 10 dB steps, and runs on two 1.5 V AA batteries (included) for approximately 10 hours. It is simple to operate, with a mute/on switch behind a window on the handle. Always confirm the frequency range matches your receiver and complies with local regulations.