It’s a fact that this is a welder made for flux core welding and gas metal welding. Therefore, it requires a flux core wire with a diameter of 0.030 inches. Yet if this one is harder to come by in your area, you can go for a different size. It still needs to be between 0.025 inches and 0.035 inches, though. And if such a wire is used, the feed drive roller of the wire should be modified or changed along with the contact tip.