Wireless system. I used it once for a live performance with a guitar. Operation confirmed. The SIEM-2 wireless mono in-ear monitoring system provides a high-quality audio experience. - Model Name: SIEM-2 - Type: Mono in-ear monitoring system - Included Accessories: Earphones, Instruction Manual, AC Adapter - Brand: JTS - Configuration: Transmitter, Receiver, Monitor Speaker - Connection Type: Wireless Thank you for viewing.