Trail Tech 7003-AC01 Universal AC Voltage Regulator Improved Universal AC Voltage Regulator with Adjustable Output Universal AC Voltage Regulator limits voltage to 12.0-16.0 volts for AC systems Conditions circuit to eliminate electrical spikes, protect from lamp blow-outs, and reduce flicker and dimming "Dial-a-Brightness" allow you to adjust light output at the cost of lamp life for halogen and quartz lights At 14+ VAC setting, the lamps will approach HID lumens (70 percent) but lamp life is short (good for racing); 25 hour lamp life At standard setting, about 13.8 VAC, the lamps should last about 500 hours, at minimum setting, the lamps are not as bright as HID (30 percent), but last over 1,000 hours