Used ZOOM RhythmTrak RT-223, foot switch FS01, and genuine power adapter. There are some scratches, rust, and dirt, but no major damage. Operation has been confirmed as follows, with no problems: The button battery inside the RT-223 main unit has been modified to a socket for easy replacement, and the button battery has been replaced (see photo 12). The following operations have been confirmed and are problem-free: ・Operation confirmed with both AC adapter and dry batteries. ・Rhythm function and STORE function work without issue. ・VOL knob operation, OUTPUT cable connection, Line IN connection, and audio input/output via Phone output are all working without issue, and there is no scratchy noise. ・Knobs and switches operate without malfunction. ・Performance via MIDI IN signal is working without issue. ・Foot switch operation is working without issue. ※There is fluorescent highlighting on a few pages of the instruction manual (see photo 20). ＜Product Contents＞ ・ZOOM RhythmTrak RT-223 main unit ・ZOOM RT-223 instruction manual ・ZOOM RT-223 genuine power adapter ・ZOOM FS01 main unit