Weller WXA2 2 Channel Power Unit is for operation with external compressed air and is ESD-safe. The WXA2 features equipotential balance, intelligent tool detection, and unit data traceability aswell as a USB interface. In the WXA2, the amount of air can be controlled using the rotary knob. The Weller WXA2 2 Channel Power Unit has 3 separate operating modes, Operating mode level 1 the air flow continues for as long as the button on the hot-air iron or foot switch is pressed. Operating mode level 2 if the button is pressed once, the hot-air flow continues for between 0 and 300 seconds, stopping at the end of the set time. Operating mode level 3 the WXHAP 200 switches on with one press of the button and off with the second press.