This CAT remanufactured 3406E fuel injector includes a new actuator assembly - spill valve, solenoid, NOP spring, washer, shim and stop in each injector. All O-rings have been replaced, and injector comes with a 90 day, no-hassle warranty. and has a 12 month, unlimited-mileage warranty. The nozzle has been 100% flow tested. There is an additional core charge of $175. You purchase your fuel injectors from us and pay the core charge up front. We allow you 30 days to send your core injectors back to us. MUST ADD ACE PRODUCT CODE # 9FI630957COR to the order.