Shure ADTD Axient Digital PSM Dual Wireless Transmitter -- The ADTD reimagines in-ear monitoring wireless transmission. Provides faultless performance in the most challenging RF environments. Available with standard AC powering or DC. Available frequency bands: G57 (470-608 MHz); K54 (606-608, 614-616, 652-663 MHz); and X55 (941-960 MHz).