This is the QX500.1d. This amp is 2ohm stable and will do over 750rms and will run at 1ohms and put out even more clean power. It has a built in subsonic filter, I will also include a LPL remote bass knob, 4guage wiring kit. This amp has a 2 year warranty on it. Have all papers and reciept showing i payed over $300 for it. Im asking $225 plus shipping.