Sennheiser 509169 Spectera DAD AntennaEach bidirectional Spectera SEK bodypack manages both an IEM IFB and a mic line stream simultaneously. Plus, they allow for full remote control and monitoring, via identical RF connection, of IEM volume, audio level and settings, RF health, battery status, and more via LinkDesk software. Variants include UHF (470 608 MHz and 630 698 MHz) or 1G4 (1350 1400 MHz and 1435 1525 MHz).