Voltage?

I was thinking about buying a 400W balast that works for both MH and HPS, and it says it comes with either a 140 volt power cord or 240, any info on the difference?

140 would be your standard wall socket plug, usually called 110v-120v. 240v is basically two different legs of 120v to create 240 volts, that's what the bigger stuff in your house uses like the dryer and A/C unit.