This Bosch common rail injector is used on the 2004.5-05 GM pickups with 6.6L LLY Duramax engine. It is remanufactured by Bosch. It is the original equipment (OE) injector not an aftermarket or will fit. This is an exchange item requiring the return of the old core/cores. CORE CHARGE: A core charge of $250.00 will be applied to your credit card account, if the old core is are returned within 30 days you will get credit. Feel free to call our parts department at 800-891-8038 with any questions.