These are our in house rebuilt 155cc injector with your choice of upgraded new nozzle. We recommend a 30% nozzle but it can be paired with any of the nozzles we offer. This is NOT a exchange program we rebuild injectors you send us and return the same injector to you. So you know exactly what you are getting back. The reason for this is at this time there are still non serviceable parts in these injectors that if worn out we cannot repair. So you know the condition of injector you are getting back and mileage. These injectors are completely disassembled cleaned and all measurements taken and checked for proper clearances. If they are beyond repair we will call you and proceed from there. These are reassembled with a brand new not reman nozzle, new nozzle lift spring, new piston return spring, all new seals and gaskets. These carry a 6 month warranty.