B-7PSM NUX Wireless in-ear monitor system XSWIEM/B Sennheiser XSW-1 in-ear monitor system XSWIEM/E Sennheiser XSW-1 in-ear monitor system XSWIEM-EK/B Sennheiser XSW-1 in-ear monitor bodypack to expand exsisting XSW-IEM setups XSWIEM-EK/E Sennheiser XSW-1 in-ear monitor bodypack to expand exsisting XSW-IEM setups ewIEM/A Sennheiser EW G4 in-ear monitor system ewIEM/B Sennheiser EW G4 in-ear monitor system ewIEM/E Sennheiser EW G4 in-ear monitor system ewIEM-TW/A Sennheiser EW G4 twin in-ear monitor system ewIEM-TW/B Sennheiser EW G4 twin in-ear monitor system