40 Amp Continuous Rating, 100% Duty Cycle. Variable Voltage Control 5-15 VDC. Voltage Control Knob has center detent at 13.5 VDC. Overload & short-circuit protection with Current Foldback at approximately 42 Amp. Over Temperature Protection; variable speed fan automatically controlled for quiet operation. 120 VAC operation only; for 240 volt operation, see the GZV-4000-220Volt version of this power supply.