The ISO2 provides two independent channels of line level isolation and/or conversion of signals from unbalanced to balanced. 1 and 2 Inputs (Dual female XLR jacks) For input of signal(s) from the source(s). Each XLR accepts a balanced connection, the 1⁄4” jacks accept balanced or unbalanced connections. Do not use the XLR and 1⁄4” on an individual channel at the same time. 1 Output (Male XLR) Provides a balanced output connection for corresponding #1 input jack. 2 Output (Male XLR) Provides a balanced output connection for corresponding #2 input jack. LIFT / GND (Buttons X 2) Disconnects the ground between the input(s) and the XLR output(s) when set to the LIFT position to help eliminate hum. Ground remains connected when set to the GND position. REV / Ø (Button) Reverses the polarity of pins 2 and 3 of output XLR #2 ONLY. This is useful when connecting to equipment whose outputs have reversed polarity or may be used to correct for a mis-wired cable.