Shure QLXD1 G51, Digital UHF Pocket Transmitter, Frequency band G51 (470 - 534 MHz), 24 bit / 48 kHz Audio signal, AES-256 Encryption for tap-proof transmission, Up to 72 MHz switching bandwidth, 22 Compatible channels in an 8 MHz TV band, Switchable transmission power 1/10 mW, 120 dB Dynamic range, Metal casing with 4-pin TQG connection, Transmitter operation with 1.5 V AA batteries - optionally also with SB 900 lithium ion rechargeable battery