wire with a cross section of 0.75 mm. Before buying, I advise potential buyers to go to the atcom website and see a picture with the correct direction of the connector bend. The picture on the market is wrong. Some pros: works. sits tightly in the power supply connector, does not play. allows you to put the case of the system unit in a tight wall. Got cons: copper plated aluminium. I would like the wire to be copper, since this company has other models with copper.