The only thing you need to connect your Serial PLM (2413S) to Polisy or eisy.
Please note that you do not need this kit if you already have a USB PLM. You only need this kit if you have a 2412 or 2413S PLMs.
Please note that PLMs uses an esoteric pinout and thus off-the-shelf cables do not work. We do not provide support if you assemble this part yourself.