Palmer MI PGA03 Y-Splitter for Guitars

A splitter box with galvanic isolation that distributes a guitar signal to two amplifiers. Can be operated with a power supply unit (not included) or with batteries.
The Palmer Y-box's FET input circuitry adapts your guitar signal, driving a transformer, which routes the ungrounded signal to the output.
The Y-box also serves as a line driver for long leads, and it allows for phase reversal of the AMP 2 output.