Heavy-Duty IGBT Power Modules increase reliability and performance 2T/4T/ Pedal operation modes with additional 2T/4T mode for torch amptrol operation. Wave form control in AC provides 4 wave forms: Sine, Triangular, Soft Square and Advanced Square Wave Pulse up to 500Hz in DC, 250 Hz AC Wave form control in AC provides 4 wave forms: Sine, Triangular, Soft Square and Advanced Square Wave 10Hz Advanced AC Pulse mode improves penetration on thicker metals, and can reduce warping and burn through on thinner metals No hidden menus to access or complicated set up routines Arc force control, Hot start time, Hot start intensity settings for Stick welding to improve performance 240V 1 phase operation 6010/Cellulose Stick welding capability If you need the most power the PowerTIG 400 EXT is the latest and most powerful member of Everlast's PowerTIG series of TIG/Stick welders. With 240V single phase power, it delivers a full 400A in TIG mode, thanks to it's constant-on, high output fan cooling. That's enough power to weld most every TIG welding chore found in most any shop and do it without stopping every minute or so to rest. Compared to other competitors in it's class it's also more duty cycle in single phase than any other welder as well with a 35% duty cycle at the full 400A in TIG mode. The welder also has a generous 270A output @ 35% duty cycle in stick mode which means it has enough stick power to tackle almost any common stick fabrication or repair chore with up to 1/4" electrode. For TIG,the Advanced AC pulse feature this unit is capable of delivering considerably more TIG welding capability (thickness) than any other unit in it's class. This unit is designed to get the job done where thicker plate and weldments are common. As far as features go, the PowerTIG 400EXT doesn't fall short either. It has all the familiar features you've come to expect in the EXT digital class of welders from Everlast. as far as basic layout and operation are concerned for those shops that want to upgrade to a heavier unit without retraining personnel. Duty cycle is a favorable 35% at maximum output and is able to go the distance with its high output constant-on fan design. As far as low end performance goes, this brute is far from clumsy. It features a respectable 5A DC and 10A AC low end operation capability. Just add a power plug, gas and Tungsten, and you are ready to weld.