The SK-XSW-A Bodypack Transmitter from Sennheiser is designed to be paired with an EM-XSW1-A or EM-XSW-2 receiver. It can be used to capture audio for live stage applications and features automatic frequency management, which offers up to ten coordinated frequency presets for wireless connections. The transmitter is sweat-resistant and can withstand even the toughest stress in everyday on-stage use.