Listing is for 1, OEM DODGE RAM CUMMINS Engine Control Unit. (ECU,ECM,PCM,PCU...) P/N: 3957300 Please make sure to match your original P/N when replacing. Do not buy this unit if your P/N does NOT match. CORE RETURN: You must send acceptable core to recieve $200 refund and to activate your 1 YEAR WARRANTY Simply pack your old pcm into the packaging provided, attach a shipping label and let us know your core return is heading back to us. We will start your 1 year warranty once its received. I WILL INCLUDE FOR FREE AFTER PURCHASE: Flash updating of the latest Calibrations (ecu programming). VIN programming to match your car. This ECU will be plug and play to your car. Please include your VIN in purchase notes or message it to us after purchase. IF you do not provide your VIN with in 24hrs the pcm will be sent as is and you will need to program it yourself.