For easy polarity switching. Example: DC-stick root pass on pipe & DC+ stick for hot, full and cap passes. Also for an easy process change. Example: DC+ stick root pass on pipe & DC Innershield® self-shielded flux-cored wire for hot, fill and cap passes. 6-pin & 14-pin remote connections can be made to this unit. For all Lincoln® Chopper Technology® engine-driven welders. Mounts on roof with K2663-1 Docking Kit.