Galaxy AS-900-4-K1 4-Person Wireless In Ear Monitor System (K1 - 630.2MHz Frequency) "AS-900T wireless transmitter AF L/R indicator Transmits in stereo or mono Fixed frequency XLR/1/4"" combo input RF output 10mW Single rackmount transmitter AS-900R wireless receiver Headphone out: volume control 80mW 2 ""AA"" batteries RF indicator Low-battery indicator 3.2oz (90g)" AF L/R indicator Transmits in stereo or mono Fixed frequency "XLR/1/4"" combo input"